Adding a development dependency that had not been mentioned

Author: ch1ago

oauth.gemspec

@@ -39,4 +39,5 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency("webmock", "< 2.0")
   spec.add_development_dependency("codeclimate-test-reporter")
   spec.add_development_dependency("simplecov")
+  spec.add_development_dependency("rest-client")
 end