com.android.build.transform.api.TransformException

Another thing to watch for, is that you don't use

compile 'com.google.android.gms:play-services:8.3.0'

That will import ALL the play services, and it'll only take little more than a hello world to exceed the 65535 method limit of a single dex APK.

Always specify only the services you need, for instance:

compile 'com.google.android.gms:play-services-identity:8.3.0'
compile 'com.google.android.gms:play-services-plus:8.3.0'
compile 'com.google.android.gms:play-services-gcm:8.3.0'

Try adding multiDexEnabled true to your app build.gradle file.

 defaultConfig {
    multiDexEnabled true
}

EDIT:

Try Steve's answer first. In case it happens frequently or first step didn't help multiDexEnabled might help. For those who love to dig deeper here is couple similar issues (with more answers):

:app:dexDebug ExecException finished with non-zero exit value 2

Error:Execution failed for task ':app:dexDebug'. com.android.ide.common.process.ProcessException

I just had to Clean my project and then it built successfully afterwards.