add test gems

Gemfile.lock

@@ -56,6 +56,7 @@ GEM
     coffee-script-source (1.10.0)
     concurrent-ruby (1.0.2)
     debug_inspector (0.0.2)
+    docile (1.1.5)
     dotenv (2.1.1)
     dotenv-rails (2.1.1)
       dotenv (= 2.1.1)
@@ -99,12 +100,15 @@ GEM
       nokogiri (>= 1.5.9)
     mail (2.6.4)
       mime-types (>= 1.16, < 4)
+    metaclass (0.0.4)
     method_source (0.8.2)
     mime-types (3.1)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2016.0521)
     mini_portile2 (2.1.0)
     minitest (5.9.1)
+    mocha (1.2.1)
+      metaclass (~> 0.0.1)
     multi_json (1.12.1)
     multi_xml (0.5.5)
     multipart-post (2.0.0)
@@ -177,6 +181,11 @@ GEM
       sprockets (>= 2.8, < 4.0)
       sprockets-rails (>= 2.0, < 4.0)
       tilt (>= 1.1, < 3)
+    simplecov (0.13.0)
+      docile (~> 1.1.0)
+      json (>= 1.8, < 3)
+      simplecov-html (~> 0.10.0)
+    simplecov-html (0.10.0)
     spring (2.0.0)
       activesupport (>= 4.2)
     spring-watcher-listen (2.0.1)
@@ -228,6 +237,7 @@ DEPENDENCIES
   jquery-ui-rails
   listen (~> 3.0.5)
   lograge
+  mocha
   omniauth (= 1.3.1)
   omniauth-google-oauth2 (= 0.4.1)
   omniauth-twitter (= 1.2.1)
@@ -236,6 +246,7 @@ DEPENDENCIES
   rails (~> 5.0.0, >= 5.0.0.1)
   rails-timeago (~> 2.0)
   sass-rails (~> 5.0)
+  simplecov
   spring
   spring-watcher-listen (~> 2.0.0)
   sqlite3