Add 'event' to expected_events_params in controller

This is a new part of Rails 4 which is in the 'private' section in the controller and adds additional security to the app. Instead of using attributes accessible in the model, these have to be set in the controller. 

Also, when using validates_presence_of, this has to be included in the model AND in the controller now as well.
Change Alarm Trigger column name from 'type' to 'nature'

- we had to change a column name in our database because we used the word ‘type’ which is a STUPID MAGIC RAILS WORD THAT WE CAN’T USE ANYWHERE. We didn’t know this when we started. We decided to call it ‘nature’ instead. 
- To do this, we had to do a rails generate migration rename_alarm_triggers_column 
- this creates a ‘change’ method in the migration which we then had to fill in with the things we wanted to change. 
- we used the method rename_column to rename a column in the the alarm_triggers table. We replaced type  with nature. THE ORDER HERE IS IMPORTANT. (in db/migrate file)
- after doing that we saved it and then did a rake db:migrate.
Change 'type' to 'nature' in all Alarm Triggers files
Add title, nature and action to alarm_trigger_params

We do this so that the user can update these three parameteres via the form.