Fix issues with request descriptor matching and add battery of explicit tests for descriptor precedence lookup. closes #1513
Fix RKResponseMapperOperation matchingResponseDescriptors to check for method match
Merge pull request #1517 from segiddins/bugfix/responsemapperoperation-matchingresponsedescriptor

Fix RKResponseMapperOperation matchingResponseDescriptors to check for method match
Remove explicit `bundle install` since Travis now prioritizes Bundler ahead of CocoaPods (see travis-ci/travis-ci#1276)
Enable support for mapping values in @metadata as relationships. fixes #1506