Add development dependencies.

Author: beauby

jsonapi-renderer.gemspec

@@ -12,4 +12,7 @@ Gem::Specification.new do |spec|
 
   spec.files         = Dir['README.md', 'lib/**/*']
   spec.require_path  = 'lib'
+
+  spec.add_development_dependency 'rake', '~> 11.3'
+  spec.add_development_dependency 'rspec', '~> 3.5'
 end