Remove coveralls as its unused

Gemfile

@@ -303,7 +303,6 @@ group :development, :test do
   gem 'rubocop', '~> 0.40.0', require: false
   gem 'rubocop-rspec', '~> 1.5.0', require: false
   gem 'scss_lint', '~> 0.47.0', require: false
-  gem 'coveralls', '~> 0.8.2', require: false
   gem 'simplecov', '~> 0.11.0', require: false
   gem 'flog', require: false
   gem 'flay', require: false

Gemfile.lock

@@ -141,12 +141,6 @@ GEM
     colorize (0.7.7)
     concurrent-ruby (1.0.2)
     connection_pool (2.2.0)
-    coveralls (0.8.13)
-      json (~> 1.8)
-      simplecov (~> 0.11.0)
-      term-ansicolor (~> 1.3)
-      thor (~> 0.19.1)
-      tins (~> 1.6.0)
     crack (0.4.3)
       safe_yaml (~> 1.0.0)
     creole (0.5.0)
@@ -729,8 +723,6 @@ GEM
     teaspoon-jasmine (2.2.0)
       teaspoon (>= 1.0.0)
     temple (0.7.7)
-    term-ansicolor (1.3.2)
-      tins (~> 1.0)
     test_after_commit (0.4.2)
       activerecord (>= 3.2)
     thin (1.6.4)
@@ -751,7 +743,6 @@ GEM
       mime-types
       multi_json (~> 1.7)
       twitter-stream (~> 0.1)
-    tins (1.6.0)
     turbolinks (2.5.3)
       coffee-rails
     twitter-stream (0.1.16)
@@ -841,7 +832,6 @@ DEPENDENCIES
   chronic_duration (~> 0.10.6)
   coffee-rails (~> 4.1.0)
   connection_pool (~> 2.0)
-  coveralls (~> 0.8.2)
   creole (~> 0.5.0)
   d3_rails (~> 3.5.0)
   database_cleaner (~> 1.4.0)

lib/tasks/test.rake

@@ -6,8 +6,6 @@ task :test do
 end
 
 unless Rails.env.production?
-  require 'coveralls/rake/task'
-  Coveralls::RakeTask.new
   desc "GitLab | Run all tests on CI with simplecov"
-  task :test_ci => [:rubocop, :brakeman, 'teaspoon', :spinach, :spec, 'coveralls:push']
+  task test_ci: [:rubocop, :brakeman, 'teaspoon', :spinach, :spec]
 end