Fixes NPE when return types are void

fixes #130, #139, #146
[maven-release-plugin] prepare release swagger-springmvc-0.6.5
[maven-release-plugin] prepare for next development iteration
Updated the documentation to 0.6.5
Merging from rel-0.6
Tests that exercise the documentation APIs for a class that inherits its RequestMappings from an interface
Added some sensible ignores
Support documentation APIs for a class that inherits its RequestMappings from an interface
Update readme.md
Merge pull request #158 from sverhagen/master

Fix for when the RequestMapping(s) are declared on interfaces that the controller inherits
Fixes wildcard replacement for generic types that dont have the same shape

for e.g. When SomeType<WildcardType> maps to Wildcard

closes #168
Merge branch 'rel-0.6'
Added tests to mirror the spring-mvc-example project
Fixed the pom file
Removed Lombok dependencies
Changed unnecessary warnings to debug
Reformatting configuration class
Moved to using parameterized tests using groovy
Refactored controllers to its own package
Migrated test package to sample