Merge pull request #12 from Ragowit/master

Added Paladin and implemented Avenging Wrath
Implemented Paladin hero power
Update readme.md

Added link to Travis CI build status
Implemented Spell Power as per Issue #13

Also refactored Keeper of the Grove, since its battlecry wouldn't target a
Faerie Dragon, whereas now it will.

Implemented Kobold Geomancer for testing purposes
Refactored CARD_STATUS to CARD_RARITY as per issue #11
Merge pull request #2 from danielyule/master

Getting the latest code from master