Populate timestamp of CustomButtonEvent.

[lfu]

A timestamp without value would break MiqReport.

Followup of #17764.

https://bugzilla.redhat.com/show_bug.cgi?id=1511126

@miq-bot assign @gmcculloug
@miq-bot add_label automate, enhancement, events
cc @skateman

[gmcculloug]

Would be good to use Timecop.freeze so we can validate this time instead of only checking that it is not nil.

[gmcculloug]

Tests are failing because the time is losing some precision:

expected: 2018-08-24 13:28:43.030727136 +0000
     got: 2018-08-24 13:28:43.030727000 +0000

Looking over other specs for examples I see be_within(0.1).of being used:
https://github.com/ManageIQ/manageiq/blob/master/spec/models/drift_state/purging_spec.rb#L41

Or you can set the time like this example: Timecop.freeze(Time.utc(2015, 1, 2, 4, 30))
https://github.com/ManageIQ/manageiq/blob/master/spec/models/dialog_field_date_time_control_spec.rb#L120

[skateman]

Thanks 🍻

[miq-bot]

Checked commit lfu@54c0388 with ruby 2.3.3, rubocop 0.52.1, haml-lint 0.20.0, and yamllint 1.10.0
2 files checked, 0 offenses detected
Everything looks fine. ⭐