Feature/code coverage

Ran some code coverage tools to find test gaps and easy refactoring targets. I'll probably do more on this front in the future but this first wave moved the code coverage from 42.6% (Java) and 26.2% (Groovy) to 50.0%/26.7%.

The more interesting changes are the removal of deepCopy overrides from a bunch of spells; removing the massive Minion constructor since it wasn't really being used and was really hard to read; and removing the summoned and transformed fields.