Initial swipe up gesture added to hero
Test
Adding swipe down function. Ground/Hero contact working.
Merge branch 'vincentBranch' of https://github.com/tnahvu/SkaterBrad into GestureBranch

Conflicts:
	SkaterBrad/GameScene.swift
Add swipe down, hero ground contact
resolved master conflicts
Merging background work and contact work
First Initial Pull Request
Merge pull request #5 from tnahvu/gestureBranch

Gesture branch