Updated calendar creation resource to only trigger when inputs are changed

[marcus-bcl]

Tested in delius-core-dev.

1. First apply forces replacement:

   
   # module.calendar.null_resource.create_calendar must be replaced
   -/+ resource "null_resource" "create_calendar" {
     ~ id       = "7710116841605799181" -> (known after apply)
     ~ triggers = { # forces replacement
         - "always_run"           = "2020-11-11T10:01:36Z" -> null
         + "calendar_name"        = "delius-core-dev-calendar"
         + "calender_content_doc" = "file://files/calendar_content"
         + "region"               = "eu-west-2"
       }
   }

Plan: 1 to add, 0 to change, 1 to destroy.

module.calendar.null_resource.create_calendar: Destroying... [id=7710116841605799181] module.calendar.null_resource.create_calendar: Destruction complete after 0s module.calendar.null_resource.create_calendar: Creating... module.calendar.null_resource.create_calendar: Provisioning with 'local-exec'... module.calendar.null_resource.create_calendar (local-exec): Executing: ["/bin/sh" "-c" "sh scripts/create_calendar.sh file://files/calendar_content delius-core-dev-calendar eu-west-2"] module.calendar.null_resource.create_calendar: Creation complete after 2s [id=427545949344817336]

Apply complete! Resources: 1 added, 0 changed, 1 destroyed. Releasing state lock. This may take a few moments...

Outputs:

calendar_name = delius-core-dev-calendar

2. Subsequent applies don't trigger any change (unless calendar_name or calender_content_doc are updated):

Apply complete! Resources: 0 added, 0 changed, 0 destroyed.

Outputs:

calendar_name = delius-core-dev-calendar