CI: create a badge image for code coverage

Author: phw

README.md

@@ -1,7 +1,6 @@
 # Ruby bindings for MusicBrainz libdiscid
 [![Gem Version](https://badge.fury.io/rb/discid.svg)](http://badge.fury.io/rb/discid)
-[![Maintainability](https://api.codeclimate.com/v1/badges/50e356f4260a127af75b/maintainability)](https://codeclimate.com/github/phw/ruby-discid/maintainability)
-[![Test Coverage](https://api.codeclimate.com/v1/badges/50e356f4260a127af75b/test_coverage)](https://codeclimate.com/github/phw/ruby-discid/test_coverage)
+[![Test Coverage](https://phw.srht.site/ruby-discid/coverage/coverage_badge_total.svg)](https://phw.srht.site/ruby-discid/coverage/)
 
 ## About
 ruby-discid provides Ruby bindings for the MusicBrainz DiscID library [libdiscid](http://musicbrainz.org/doc/libdiscid).

discid.gemspec

@@ -36,5 +36,6 @@ Gem::Specification.new do |spec|
   if (RUBY_VERSION.split('.').map{|s|s.to_i} <=> [2, 4, 0]) >= 0
     spec.add_development_dependency "simplecov"
     spec.add_development_dependency "simplecov_json_formatter"
+    spec.add_development_dependency "simplecov-small-badge"
   end
 end

test/helper.rb

@@ -16,10 +16,12 @@
 begin
   require 'simplecov'
   require "simplecov_json_formatter"
+  require 'simplecov_small_badge'
 
   SimpleCov.formatter = SimpleCov::Formatter::MultiFormatter.new([
     SimpleCov::Formatter::JSONFormatter,
-    SimpleCov::Formatter::HTMLFormatter
+    SimpleCov::Formatter::HTMLFormatter,
+    SimpleCovSmallBadge::Formatter
   ])
   SimpleCov.start do
     add_filter "/test/"