Adding PropertyMapImporter.
Fixing copy paste error that replaced a JsonImporter test with a PropertyMapImporter test.
Removing Expect class from importer.dart
Removing Expect class from tests. Modifying calls to expect. The first argument is the actual while the second contains a matcher to compare to.
Fix stack overflow bug. https://github.com/johnmccutchan/asset_pack/issues/6
Adding the ability to pass in a PropertyMapConfig to the PropertyMapImporter. Change fallback to return null,
Merging from master. Removing Expect class code.
Merge pull request #5 from donny-dont/master

Adding PropertyMapImporter