Improve KryoInjection
Add test case for serialization of custom objects.

This doubles as example code for creating customized KryoBijection
subclasses that serialize custom classes that have a bijection to a
primitive type.
Merge pull request #51 from schmmd/customtest

Add test case for serialization of custom objects.
Update test case actually use the custom KryoInjection and move the case classes inside the Spec.
Merge pull request #52 from schmmd/customtestfix

Update test case actually use the custom KryoInjection.
Merge pull request #44 from twitter/feature/faster-injection

Improve KryoInjection
fix tests
Merge pull request #53 from twitter/feature/fix_tests

Fix Test Breakage from Injection updates