serviceworker-rails.gemspec in serviceworker-rails-0.5.2 vs serviceworker-rails.gemspec in serviceworker-rails-0.5.3

- old
+ new

@@ -27,6 +27,7 @@
   spec.add_development_dependency "minitest", "~> 5.0"
   spec.add_development_dependency "rack-test"
   spec.add_development_dependency "rubocop", "0.46.0"
   spec.add_development_dependency "rails"
   spec.add_development_dependency "appraisal", "~> 2.1.0"
+  spec.add_development_dependency "coveralls"
 end