++xcconfigs
++specta, ++expecta for arm64 support
Merge pull request #192 from github/arm64

Update dependencies for arm64 tests
++Configuration
Fix a crash when receving something different than a NSDictionary to
build the model, which can easily happen if the json structure changes
Add test to check it doesn't break when using a wrong data type as dictionary
Merge branch 'master' into fixCrashWhenBuildingTheModel
Fix the test because of merge
Improve error description of the error for invalid json received
Fix a couple of syntax issues based on the comments in the PR
Make JSONKeyPathForKey: public
Rename to JSONKeyPathForPropertyKey:
Add documentation to -JSONKeyPathForPropertyKey:
Merge pull request #197 from dcordero/fixCrashWhenBuildingTheModel

Fix a crash when receving something different than a NSDictionary
Merge pull request #199 from github/keypath-hook

Expose -JSONKeyPathForKey:
Specta/Expecta -> XCTest
Remove now-defunct mtl_firstObject
Add MTLPropertyAttributes class to replace extobjc methods
Move away from extobjc
Remove deprecated methods.