simplecovのバージョンを0.18未満にする

CodeClimateが対応していないため。

codeclimate/test-reporter#418

Gemfile

@@ -108,9 +108,13 @@ end
 
 group :test do
   gem 'rake'
-  gem 'simplecov'
   gem 'rubocop'
   gem 'rubocop-rails'
+
+  # Workaround for cc-test-reporter with SimpleCov 0.18.
+  # Stop upgrading SimpleCov until the following issue will be resolved.
+  # https://github.com/codeclimate/test-reporter/issues/418
+  gem 'simplecov', '~> 0.10', '< 0.18'
 end
 
 group :development do

Gemfile.lock

@@ -129,6 +129,7 @@ GEM
       thor (>= 0.14, < 2.0)
     jquery-ui-rails (6.0.1)
       railties (>= 3.2.16)
+    json (2.3.1)
     jwt (2.2.2)
     kaminari (1.2.1)
       activesupport (>= 4.1.0)
@@ -274,10 +275,11 @@ GEM
       rails (>= 3.0)
     simple_enum (2.3.2)
       activesupport (>= 4.0.0)
-    simplecov (0.19.0)
+    simplecov (0.17.1)
       docile (~> 1.1)
-      simplecov-html (~> 0.11)
-    simplecov-html (0.12.2)
+      json (>= 1.8, < 3)
+      simplecov-html (~> 0.10.0)
+    simplecov-html (0.10.2)
     sorcery (0.15.0)
       bcrypt (~> 3.1)
       oauth (~> 0.4, >= 0.4.4)
@@ -356,7 +358,7 @@ DEPENDENCIES
   simple-navigation
   simple_calendar (~> 2.0)
   simple_enum
-  simplecov
+  simplecov (~> 0.10, < 0.18)
   sorcery
   spring
   sysexits