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
Merge pull request #197 from dcordero/fixCrashWhenBuildingTheModel

Fix a crash when receving something different than a NSDictionary