Squish Tests: Alarms button

As a developer I would like to verify the following behaviour using Squish:

- Trigger an alarm.
- Verify that the `Alarms` perspective button has the correct text and is flashing red.
- View the alarms.
- Verify that the `Alarms` perspective button is now solid red.

#### Additional info:
Can use the `background` property of the perspective button to verify the colour. By checking for a short duration to see if the property changes we should be able to verify if the button is flashing.

As `Alarms` is currently the default perspective all alarms will automatically be viewed, so be sure to change the perspective before triggering an alarm.