Support mute_time_intervals for Alertmanager

[djordjeparovic]

Pull Request (PR) description

Support mute_time_intervals for Alertmanager config

This Pull Request (PR) fixes the following issues

If user defines something like:

prometheus::alertmanager::mute_time_intervals:
  - name: business_hours
    time_intervals:
      - weekdays: [ 'monday','tuesday','friday' ]
        times:
          - start_time: '16:00'
            end_time:   '23:59'
          - start_time: '00:00'
            end_time:   '07:00'

it won't be picked up, and therefore create a configuration error on other places "missing definition for business_hours".

[bastelfreak]

can you please add some unit tests for the change, add puppet-strings documentation at the top of the file and enforce the datatype for the array elements?

[bastelfreak]

@djordjeparovic can you please rebase against our latest master branch, take a look at the failing tests and and your example as a unit test?

[treydock]

@bastelfreak This can be closed, was picked up in #563 with @djordjeparovic set as Co-Author.