diff --git a/poetry.lock b/poetry.lock
index de76ce5..a1d7def 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -209,17 +209,17 @@ python-versions = "*"
 
 [[package]]
 name = "sphinx"
-version = "3.3.1"
+version = "4.1.2"
 description = "Python documentation generator"
 category = "dev"
 optional = false
-python-versions = ">=3.5"
+python-versions = ">=3.6"
 
 [package.dependencies]
 alabaster = ">=0.7,<0.8"
 babel = ">=1.3"
 colorama = {version = ">=0.3.5", markers = "sys_platform == \"win32\""}
-docutils = ">=0.12"
+docutils = ">=0.14,<0.18"
 imagesize = "*"
 Jinja2 = ">=2.3"
 packaging = "*"
@@ -228,15 +228,15 @@ requests = ">=2.5.0"
 snowballstemmer = ">=1.1"
 sphinxcontrib-applehelp = "*"
 sphinxcontrib-devhelp = "*"
-sphinxcontrib-htmlhelp = "*"
+sphinxcontrib-htmlhelp = ">=2.0.0"
 sphinxcontrib-jsmath = "*"
 sphinxcontrib-qthelp = "*"
-sphinxcontrib-serializinghtml = "*"
+sphinxcontrib-serializinghtml = ">=1.1.5"
 
 [package.extras]
 docs = ["sphinxcontrib-websupport"]
-lint = ["flake8 (>=3.5.0)", "flake8-import-order", "mypy (>=0.790)", "docutils-stubs"]
-test = ["pytest", "pytest-cov", "html5lib", "typed-ast", "cython"]
+lint = ["flake8 (>=3.5.0)", "isort", "mypy (>=0.900)", "docutils-stubs", "types-typed-ast", "types-pkg-resources", "types-requests"]
+test = ["pytest", "pytest-cov", "html5lib", "cython", "typed-ast"]
 
 [[package]]
 name = "sphinxcontrib-applehelp"
@@ -264,11 +264,11 @@ test = ["pytest"]
 
 [[package]]
 name = "sphinxcontrib-htmlhelp"
-version = "1.0.3"
+version = "2.0.0"
 description = "sphinxcontrib-htmlhelp is a sphinx extension which renders HTML help files"
 category = "dev"
 optional = false
-python-versions = ">=3.5"
+python-versions = ">=3.6"
 
 [package.extras]
 lint = ["flake8", "mypy", "docutils-stubs"]
@@ -299,7 +299,7 @@ test = ["pytest"]
 
 [[package]]
 name = "sphinxcontrib-serializinghtml"
-version = "1.1.4"
+version = "1.1.5"
 description = "sphinxcontrib-serializinghtml is a sphinx extension which outputs \"serialized\" HTML files (json and pickle)."
 category = "dev"
 optional = false
@@ -335,8 +335,8 @@ six = "*"
 
 [metadata]
 lock-version = "1.1"
-python-versions = "^3.5"
-content-hash = "81acb724bb3f7bf2528136306a09c31098cde2e21263724f5b6d1a1196484782"
+python-versions = "^3.6"
+content-hash = "4e31c83bbbc271b7a134e536e11c1f95b4a252fe601000cbc353766abc2cea1f"
 
 [metadata.files]
 alabaster = [
@@ -438,20 +438,39 @@ markupsafe = [
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     {file = "MarkupSafe-1.1.1-cp35-cp35m-win_amd64.whl", hash = "sha256:9add70b36c5666a2ed02b43b335fe19002ee5235efd4b8a89bfcf9005bebac0d"},
     {file = "MarkupSafe-1.1.1-cp36-cp36m-macosx_10_6_intel.whl", hash = "sha256:24982cc2533820871eba85ba648cd53d8623687ff11cbb805be4ff7b4c971aff"},
+    {file = "MarkupSafe-1.1.1-cp36-cp36m-macosx_10_9_x86_64.whl", hash = "sha256:d53bc011414228441014aa71dbec320c66468c1030aae3a6e29778a3382d96e5"},
     {file = "MarkupSafe-1.1.1-cp36-cp36m-manylinux1_i686.whl", hash = "sha256:00bc623926325b26bb9605ae9eae8a215691f33cae5df11ca5424f06f2d1f473"},
     {file = "MarkupSafe-1.1.1-cp36-cp36m-manylinux1_x86_64.whl", hash = "sha256:717ba8fe3ae9cc0006d7c451f0bb265ee07739daf76355d06366154ee68d221e"},
+    {file = "MarkupSafe-1.1.1-cp36-cp36m-manylinux2010_i686.whl", hash = "sha256:3b8a6499709d29c2e2399569d96719a1b21dcd94410a586a18526b143ec8470f"},
+    {file = "MarkupSafe-1.1.1-cp36-cp36m-manylinux2010_x86_64.whl", hash = "sha256:84dee80c15f1b560d55bcfe6d47b27d070b4681c699c572af2e3c7cc90a3b8e0"},
+    {file = "MarkupSafe-1.1.1-cp36-cp36m-manylinux2014_aarch64.whl", hash = "sha256:b1dba4527182c95a0db8b6060cc98ac49b9e2f5e64320e2b56e47cb2831978c7"},
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     {file = "MarkupSafe-1.1.1-cp38-cp38-manylinux1_x86_64.whl", hash = "sha256:13d3144e1e340870b25e7b10b98d779608c02016d5184cfb9927a9f10c689f42"},
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+    {file = "MarkupSafe-1.1.1-cp38-cp38-manylinux2014_aarch64.whl", hash = "sha256:caabedc8323f1e93231b52fc32bdcde6db817623d33e100708d9a68e1f53b26b"},
     {file = "MarkupSafe-1.1.1-cp38-cp38-win32.whl", hash = "sha256:596510de112c685489095da617b5bcbbac7dd6384aeebeda4df6025d0256a81b"},
     {file = "MarkupSafe-1.1.1-cp38-cp38-win_amd64.whl", hash = "sha256:e8313f01ba26fbbe36c7be1966a7b7424942f670f38e666995b88d012765b9be"},
+    {file = "MarkupSafe-1.1.1-cp39-cp39-macosx_10_9_x86_64.whl", hash = "sha256:d73a845f227b0bfe8a7455ee623525ee656a9e2e749e4742706d80a6065d5e2c"},
+    {file = "MarkupSafe-1.1.1-cp39-cp39-manylinux1_i686.whl", hash = "sha256:98bae9582248d6cf62321dcb52aaf5d9adf0bad3b40582925ef7c7f0ed85fceb"},
+    {file = "MarkupSafe-1.1.1-cp39-cp39-manylinux1_x86_64.whl", hash = "sha256:2beec1e0de6924ea551859edb9e7679da6e4870d32cb766240ce17e0a0ba2014"},
+    {file = "MarkupSafe-1.1.1-cp39-cp39-manylinux2010_i686.whl", hash = "sha256:7fed13866cf14bba33e7176717346713881f56d9d2bcebab207f7a036f41b850"},
+    {file = "MarkupSafe-1.1.1-cp39-cp39-manylinux2010_x86_64.whl", hash = "sha256:6f1e273a344928347c1290119b493a1f0303c52f5a5eae5f16d74f48c15d4a85"},
+    {file = "MarkupSafe-1.1.1-cp39-cp39-manylinux2014_aarch64.whl", hash = "sha256:feb7b34d6325451ef96bc0e36e1a6c0c1c64bc1fbec4b854f4529e51887b1621"},
+    {file = "MarkupSafe-1.1.1-cp39-cp39-win32.whl", hash = "sha256:22c178a091fc6630d0d045bdb5992d2dfe14e3259760e713c490da5323866c39"},
+    {file = "MarkupSafe-1.1.1-cp39-cp39-win_amd64.whl", hash = "sha256:b7d644ddb4dbd407d31ffb699f1d140bc35478da613b441c582aeb7c43838dd8"},
     {file = "MarkupSafe-1.1.1.tar.gz", hash = "sha256:29872e92839765e546828bb7754a68c418d927cd064fd4708fab9fe9c8bb116b"},
 ]
 packaging = [
@@ -497,8 +516,8 @@ snowballstemmer = [
     {file = "snowballstemmer-2.0.0.tar.gz", hash = "sha256:df3bac3df4c2c01363f3dd2cfa78cce2840a79b9f1c2d2de9ce8d31683992f52"},
 ]
 sphinx = [
-    {file = "Sphinx-3.3.1-py3-none-any.whl", hash = "sha256:d4e59ad4ea55efbb3c05cde3bfc83bfc14f0c95aa95c3d75346fcce186a47960"},
-    {file = "Sphinx-3.3.1.tar.gz", hash = "sha256:1e8d592225447104d1172be415bc2972bd1357e3e12fdc76edf2261105db4300"},
+    {file = "Sphinx-4.1.2-py3-none-any.whl", hash = "sha256:46d52c6cee13fec44744b8c01ed692c18a640f6910a725cbb938bc36e8d64544"},
+    {file = "Sphinx-4.1.2.tar.gz", hash = "sha256:3092d929cd807926d846018f2ace47ba2f3b671b309c7a89cd3306e80c826b13"},
 ]
 sphinxcontrib-applehelp = [
     {file = "sphinxcontrib-applehelp-1.0.2.tar.gz", hash = "sha256:a072735ec80e7675e3f432fcae8610ecf509c5f1869d17e2eecff44389cdbc58"},
@@ -509,8 +528,8 @@ sphinxcontrib-devhelp = [
     {file = "sphinxcontrib_devhelp-1.0.2-py2.py3-none-any.whl", hash = "sha256:8165223f9a335cc1af7ffe1ed31d2871f325254c0423bc0c4c7cd1c1e4734a2e"},
 ]
 sphinxcontrib-htmlhelp = [
-    {file = "sphinxcontrib-htmlhelp-1.0.3.tar.gz", hash = "sha256:e8f5bb7e31b2dbb25b9cc435c8ab7a79787ebf7f906155729338f3156d93659b"},
-    {file = "sphinxcontrib_htmlhelp-1.0.3-py2.py3-none-any.whl", hash = "sha256:3c0bc24a2c41e340ac37c85ced6dafc879ab485c095b1d65d2461ac2f7cca86f"},
+    {file = "sphinxcontrib-htmlhelp-2.0.0.tar.gz", hash = "sha256:f5f8bb2d0d629f398bf47d0d69c07bc13b65f75a81ad9e2f71a63d4b7a2f6db2"},
+    {file = "sphinxcontrib_htmlhelp-2.0.0-py2.py3-none-any.whl", hash = "sha256:d412243dfb797ae3ec2b59eca0e52dac12e75a241bf0e4eb861e450d06c6ed07"},
 ]
 sphinxcontrib-jsmath = [
     {file = "sphinxcontrib-jsmath-1.0.1.tar.gz", hash = "sha256:a9925e4a4587247ed2191a22df5f6970656cb8ca2bd6284309578f2153e0c4b8"},
@@ -521,8 +540,8 @@ sphinxcontrib-qthelp = [
     {file = "sphinxcontrib_qthelp-1.0.3-py2.py3-none-any.whl", hash = "sha256:bd9fc24bcb748a8d51fd4ecaade681350aa63009a347a8c14e637895444dfab6"},
 ]
 sphinxcontrib-serializinghtml = [
-    {file = "sphinxcontrib-serializinghtml-1.1.4.tar.gz", hash = "sha256:eaa0eccc86e982a9b939b2b82d12cc5d013385ba5eadcc7e4fed23f4405f77bc"},
-    {file = "sphinxcontrib_serializinghtml-1.1.4-py2.py3-none-any.whl", hash = "sha256:f242a81d423f59617a8e5cf16f5d4d74e28ee9a66f9e5b637a18082991db5a9a"},
+    {file = "sphinxcontrib-serializinghtml-1.1.5.tar.gz", hash = "sha256:aa5f6de5dfdf809ef505c4895e51ef5c9eac17d0f287933eb49ec495280b6952"},
+    {file = "sphinxcontrib_serializinghtml-1.1.5-py2.py3-none-any.whl", hash = "sha256:352a9a00ae864471d3a7ead8d7d79f5fc0b57e8b3f95e9867eb9eb28999b92fd"},
 ]
 urllib3 = [
     {file = "urllib3-1.26.2-py2.py3-none-any.whl", hash = "sha256:d8ff90d979214d7b4f8ce956e80f4028fc6860e4431f731ea4a8c08f23f99473"},