TwidereProject/Twidere-Android — pull request #21 by Javran (2014-09-23 20:41:32+00:00)
Title: skip apk signing if file does not exist

The original `build.gradle` results in a build error if the signing file isn't present.
This patch will make it possible to compile the project without signing key.

Now simply running `./gradlew build` in project root directory should work even if a signing key isn't present.