Remove unused coveralls

Gemfile.lock

@@ -668,9 +668,9 @@ GEM
       rufus-scheduler (>= 2.0.24)
       sidekiq (>= 4.0.0)
     simple_oauth (0.1.9)
-    simplecov (0.11.2)
+    simplecov (0.12.0)
       docile (~> 1.1.0)
-      json (~> 1.8)
+      json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.0)
     sinatra (1.4.7)
@@ -952,7 +952,7 @@ DEPENDENCIES
   shoulda-matchers (~> 2.8.0)
   sidekiq (~> 4.0)
   sidekiq-cron (~> 0.4.0)
-  simplecov (~> 0.11.0)
+  simplecov (~> 0.12.0)
   sinatra (~> 1.4.4)
   six (~> 0.2.0)
   slack-notifier (~> 1.2.0)

lib/tasks/test.rake

@@ -7,5 +7,5 @@ end
 
 unless Rails.env.production?
   desc "GitLab | Run all tests on CI with simplecov"
-  task test_ci: [:rubocop, :brakeman, 'teaspoon', :spinach, :spec]
+  task test_ci: [:rubocop, :brakeman, :teaspoon, :spinach, :spec]
 end