diff --git a/Gemfile.lock b/Gemfile.lock
index 4b799fc..361456a 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -26,7 +26,7 @@ GEM
     coderay (1.1.2)
     concurrent-ruby (1.1.6)
     diff-lcs (1.3)
-    docile (1.1.5)
+    docile (1.3.4)
     ffi (1.9.25)
     formatador (0.2.5)
     guard (2.14.2)
@@ -46,7 +46,6 @@ GEM
     i18n (1.8.2)
       concurrent-ruby (~> 1.0)
     invoca-utils (0.3.0)
-    json (2.1.0)
     listen (3.1.5)
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
@@ -86,11 +85,12 @@ GEM
       rspec-core (>= 2, < 4, != 2.12.0)
     ruby_dep (1.5.0)
     shellany (0.0.1)
-    simplecov (0.15.1)
-      docile (~> 1.1.0)
-      json (>= 1.8, < 3)
-      simplecov-html (~> 0.10.0)
-    simplecov-html (0.10.2)
+    simplecov (0.21.1)
+      docile (~> 1.1)
+      simplecov-html (~> 0.11)
+      simplecov_json_formatter (~> 0.1)
+    simplecov-html (0.12.3)
+    simplecov_json_formatter (0.1.2)
     thor (0.20.0)
     thread_safe (0.3.6)
     tzinfo (1.2.7)