E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: com.example.android.movieapp2, PID: 24598
                  java.lang.RuntimeException: Unable to start activity
                  ComponentInfo{com.example.android.movieapp2/com.example.android.movieapp2.ui.main.MainActivity}:
                  java.lang.NullPointerException:
                  Attempt to invoke virtual method
                  'void android.arch.lifecycle.MutableLiveData.observe(android.arch.lifecycle.LifecycleOwner,
                  android.arch.lifecycle.Observer)' on a null object reference