java.lang.NoClassDefFoundErro when running test for Android Room

I'm getting below exception when running test for Room.

java.lang.NoClassDefFoundError: android.arch.persistence.db.framework.FrameworkSQLiteOpenHelperFactory

My gradle imports

    //Room
compile "android.arch.persistence.room:runtime:1.0.0-alpha3"
compile "android.arch.persistence.room:rxjava2:1.0.0-alpha3"
annotationProcessor "android.arch.persistence.room:compiler:1.0.0-alpha3"
androidTestCompile ("android.arch.persistence.room:testing:1.0.0-alpha3"){
    exclude module: 'gson'
}

clean and rebuild doesn't seem to help.