Add a link to a minitest q-reference

Lazy we are. And forgetful.
More Game specific tests
Ruleset testing
include the syntax check in the default task
A bunch of files to let tests properly fail

Before, the tests would fail because, of course, the files didn't exist so ruby
would error out. This time, at least they fail 'nicely'.
Include turn & bump gems
Add a code climate badge to the README
Require the version file & card class
Extract keeper tests into the keeper unit
Goal-specific tests
A lot of sample cards

To ensure we test all the aspects of goals:
 - Some goals can be defined with an 'or'
 - Some goals use categories of Keepers
 - Some goals simply match a subset of specific cards

While most goals are just a pair or triplet of other specific cards.
Some expected error handling