Add Tests

Adds tests. Increases test coverage from 30% to 70% :smile_cat: 
It looks like people prefer to put the failure under the method that should throw an exception. See http://stackoverflow.com/a/156868/553403

    try {
        toopherApi.authenticate(pairingId, terminalName);
        fail("My method didn't throw when I expected it to" );
    } catch(RequestError re){
        assertTrue(true);
    }