change gradle version and support version

[tuzhao]

we need update gradle version and android support version, because there have a compile error.

`* What went wrong:
Could not resolve all files for configuration ':app:debugCompileClasspath'.

Could not find support-fragment.jar (com.android.support:support-fragment:27.0.0).
Searched in the following locations:
https://jcenter.bintray.com/com/android/support/support-fragment/27.0.0/support-fragment-27.0.0.jar`