diff --git a/package-lock.json b/package-lock.json
index ceac4e9..3655006 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -54,7 +54,8 @@
     "acorn": {
       "version": "2.7.0",
       "resolved": "https://registry.npmjs.org/acorn/-/acorn-2.7.0.tgz",
-      "integrity": "sha1-q259nYhqrKiwhbwzEreaGYQz8Oc="
+      "integrity": "sha1-q259nYhqrKiwhbwzEreaGYQz8Oc=",
+      "optional": true
     },
     "acorn-globals": {
       "version": "1.0.9",
@@ -481,7 +482,8 @@
     "cssom": {
       "version": "0.3.8",
       "resolved": "https://registry.npmjs.org/cssom/-/cssom-0.3.8.tgz",
-      "integrity": "sha512-b0tGHbfegbhPJpxpiBPU2sCkigAqtM9O121le6bbOlgyV+NyGyCmVfJ6QW9eRjz8CpNfWEOYBIMIGRYkLwsIYg=="
+      "integrity": "sha512-b0tGHbfegbhPJpxpiBPU2sCkigAqtM9O121le6bbOlgyV+NyGyCmVfJ6QW9eRjz8CpNfWEOYBIMIGRYkLwsIYg==",
+      "optional": true
     },
     "cssstyle": {
       "version": "0.2.37",
@@ -1619,7 +1621,8 @@
     "prelude-ls": {
       "version": "1.1.2",
       "resolved": "https://registry.npmjs.org/prelude-ls/-/prelude-ls-1.1.2.tgz",
-      "integrity": "sha1-IZMqVJ9eUv/ZqCf1cOBL5iqX2lQ="
+      "integrity": "sha1-IZMqVJ9eUv/ZqCf1cOBL5iqX2lQ=",
+      "optional": true
     },
     "process-nextick-args": {
       "version": "2.0.1",
@@ -2082,6 +2085,7 @@
       "version": "0.3.2",
       "resolved": "https://registry.npmjs.org/type-check/-/type-check-0.3.2.tgz",
       "integrity": "sha1-WITKtRLPHTVeP7eE8wgEsrUg23I=",
+      "optional": true,
       "requires": {
         "prelude-ls": "~1.1.2"
       }
@@ -2213,9 +2217,9 @@
       "optional": true
     },
     "y18n": {
-      "version": "4.0.0",
-      "resolved": "https://registry.npmjs.org/y18n/-/y18n-4.0.0.tgz",
-      "integrity": "sha512-r9S/ZyXu/Xu9q1tYlpsLIsa3EeLXXk0VwlxqTcFRfg9EhMW+17kbt9G0NrgCmhGb5vT2hyhJZLfDGx+7+5Uj/w=="
+      "version": "4.0.1",
+      "resolved": "https://registry.npmjs.org/y18n/-/y18n-4.0.1.tgz",
+      "integrity": "sha512-wNcy4NvjMYL8gogWWYAO7ZFWFfHcbdbE57tZO8e4cbpj8tfUcwrwqSl3ad8HxpYWCdXcJUCeKKZS62Av1affwQ=="
     },
     "yargs": {
       "version": "13.3.2",