+raquelguimaraes WIP
+raquelguimaraes introducing shcema validation

+raquelguimaraes introducing schema validation for pacto
+taisediass adding external response validation on contract
+paolocarrasco refactoring around response validation
removing unnecessary pry call
+maxlinc +raquelguimaraes +taisediass +fernando-alves refactored api backwards compatibility
these files didn't need to be added
Cleanup the validate method on the Contract class
Merge pull request #24 from thoughtworks/schema_validation

Response validation