sinatra-swagger.gemspec in sinatra-swagger-0.3.1 vs sinatra-swagger.gemspec in sinatra-swagger-0.4.0

@@ -19,9 +19,10 @@
 
   s.required_ruby_version = '~> 2.0'
 
   s.add_dependency "json-schema", "~> 2.5", ">= 2.5.1"
   s.add_dependency "sinatra", "~> 1.4"
+  s.add_dependency "sinatra-contrib", "~>1.4"
 
   s.add_development_dependency "rake", "~> 10.4"
   s.add_development_dependency "rspec", "~> 3.0"
 end
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