def login(email, password)
      response = get('/loginUser', { email: email, password: password }, false)
      @token = response.body["valtoken"]
    end
def login(email, password)
      response = get('/loginUser', { email: email, password: password }, false)
      @token = response.body["valtoken"]
    end
Retrieve an auth token that can be used to make additional calls
 * *Raises* :
   - +AuthenticationError+ -> if PogoPlug does not like the credentials you provided