add whoosh sound when ball shot out, added new package w/ modified main for demo
Merge pull request #30 from jiangxiaoli/dev_Jenn

add whoosh sound when ball shot out, added new package w/ modified main ...
no gumball mach model & no shooting version, for demo
Merge pull request #31 from jiangxiaoli/dev_Jenn

no gumball mach model & no shooting version, for demo
add method of makeBigSphere for make gumball and gumball roll to front
update method makeBigSphere to let the gumball bounce once