Add CrimeFragmentTest.java. testArithmetic() fails, testCrimeFragmentNewInstance() passes.

In Android Studio add configuration to run unit tests.
Currently these changes are not source controlled.
In menu go to configurations box.
In pull down select Edit configurations
Click "+" to add a configuration.
Choose Android Tests.
Name: appTests
Select "Share". This adds .idea/runConfigurations/appTests.xml to git source control.
Module: app
Test: all in module
Target device: Show chooser dialog.

To run unit tests
Select configuration appTests.
Click Run.