Sprint 2 User Story 3: Battling for cards

[nickysemenza]

• Allow users to submit their BattleGroups to battle
• Allow users to monitor the status of their battle
• Indicate the winner of the battle
• Send a reward (new card) to the winner

[nickysemenza]

Added button that calls contract in 5cfbbc6, but the contract needs to be completed and i'll need to change what React calls after that's done

[harrischristiansen]

Users can create BattleGroups #24 , submit them to the queue #109, enter battle #102, and receive a reward #112

Contract complete, needs frontend