More minor bug-fixes and improvements:
- Added handling of unrecognized HTTP Methods: swagger-api/swagger-codegen#612
- Added accept header to HTTP requests for Swagger definitions: e364cb7
- Added convenience method to parse Swagger model from preloaded string: #39
- Excluded logback.xml per swagger-api/swagger-codegen#689
- Improved handling of unknown properties and old method property name #43