Force simplecov version to workaround CodeClimate bug

See: qltysh-archive/test-reporter#413

Author: n-rodriguez

ajax-datatables-rails.gemspec

@@ -32,5 +32,5 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'rake'
   s.add_development_dependency 'rspec'
   s.add_development_dependency 'rubocop'
-  s.add_development_dependency 'simplecov'
+  s.add_development_dependency 'simplecov', '~> 0.17.1'
 end