gradle build script modified

Hi I'm Kyungho. I found a bug when build a your project. That's a small bug but it was annoying. So I fixed it and send you.

gradle build script modified
	-> gradle wrapper version up (1.09 -> 1.10)
	-> android build tools 0.7 -> 0.9, 19.0.1->19.0.3

library/build.gradle bug fix
	-> release{} - occured problem (could not find method)
	-> modified - buildTypes{ release{} }