Merge pull request #88 from 3scale/fix-dependency-cve

cve: rake upgrade

Author: eguzki

3scale-api.gemspec

@@ -21,7 +21,7 @@ Gem::Specification.new do |spec|
   spec.require_paths = ['lib']
 
   spec.add_development_dependency 'bundler'
-  spec.add_development_dependency 'rake', '~> 10.0'
+  spec.add_development_dependency 'rake', '~> 13.0'
   spec.add_development_dependency 'rspec', '~> 3.8'
   spec.add_development_dependency 'webmock', '~> 3.4'
 end