Enable coverage in CI and use Codecov formatter

.github/workflows/build.yml

@@ -8,6 +8,7 @@ on:
 env:
   DISABLE_KNAPSACK: true
   TIMEZONE: UTC
+  COVERAGE: true
 
 jobs:
   test-controllers-and-serializers:

.simplecov

@@ -16,3 +16,6 @@ SimpleCov.start 'rails' do
   add_filter '/log'
   add_filter '/db'
 end
+
+require 'codecov'
+SimpleCov.formatter = SimpleCov::Formatter::Codecov

Gemfile

@@ -141,6 +141,7 @@ group :test, :development do
 end
 
 group :test do
+  gem 'codecov', require: false
   gem 'simplecov', require: false
   gem 'test-prof'
   gem 'webmock'

Gemfile.lock

@@ -152,6 +152,8 @@ GEM
     climate_control (0.2.0)
     cocaine (0.5.8)
       climate_control (>= 0.0.3, < 1.0)
+    codecov (0.5.1)
+      simplecov (>= 0.15, < 0.22)
     coderay (1.1.3)
     coffee-rails (4.2.2)
       coffee-script (>= 2.2.0)
@@ -618,6 +620,7 @@ DEPENDENCIES
   cancancan (~> 1.15.0)
   capybara
   catalog!
+  codecov
   coffee-rails (~> 4.2.2)
   combine_pdf
   compass-rails