User should be able to select a difficulty which affects creep strength

both files are needed for the difficulty level selection

import files
attach StartRoundGUI (script) to Main Camera
attach CreepSpawner (script) to Main Camera
- set size of Prefab, Amount In Round, and Spawn Delay to the amount of
rounds intended
- under Prefabs, set the Elements to the creep objects in Prefabs folder
- set the Amount In Round Elements to the amount intended to be in each
round
- set Spawn Delay Elements to the amount of time intended to be between
each creep in a round
- set Hit Points to the HP text object
- set Gold to the gold text object

attach the HPBehaviourScript to the HP text object
- set Hp to intended hit points of player
Merge pull request #17 from AndrewMackle/master

User should be able to select a difficulty which affects creep strength