remove pessimmistic versioning on rake

Author: synth

omniauth-microsoft_graph.gemspec

@@ -21,7 +21,7 @@ Gem::Specification.new do |spec|
   spec.add_runtime_dependency 'omniauth', '~> 1.1', '>= 1.1.1'
   spec.add_runtime_dependency 'omniauth-oauth2', '~> 1.6'
   spec.add_development_dependency "sinatra", '~> 0'
-  spec.add_development_dependency "rake", '~> 12.3.3'
+  spec.add_development_dependency "rake", '~> 12.3.3', '>= 12.3.3'
   spec.add_development_dependency 'rspec', '~> 3.6'
   spec.add_development_dependency "mocha", '~> 0'
 end