Add CodeCov support to .travis.yml

Inspired by the changes in
sendgrid/sendgrid-ruby#261

Closes #59.

Author: jamietanna

.travis.yml

@@ -9,6 +9,7 @@ rvm:
 before_install:
 - gem install minitest
 - gem install simplecov
+- gem install codecov
 
 notifications:
   hipchat:

ruby_http_client.gemspec

@@ -15,6 +15,7 @@ Gem::Specification.new do |spec|
   spec.test_files = spec.files.grep(/^(test|spec|features)/)
   spec.require_paths = ['lib']
 
+  spec.add_development_dependency 'codecov'
   spec.add_development_dependency 'minitest'
   spec.add_development_dependency 'rake'
   spec.add_development_dependency 'rubocop'

test/test_helper.rb

@@ -1,4 +1,7 @@
 if ENV['CI'] == 'true'
   require 'simplecov'
   SimpleCov.start
+
+  require 'codecov'
+  SimpleCov.formatter = SimpleCov::Formatter::Codecov
 end