deprecation for changing property in didInsertElement

[tsing80]

The following deprecation is trigger when using ember-cli-datepicker addon:
A property of <myapp@view:-outlet::ember4071> was modified inside the didInsertElement hook. You should never change properties on components, services or models during didInsertElement because it causes significant performance degradation. [deprecation id: ember-views.dispatching-modify-property]

This is triggered after https://github.com/wesm87/ember-datepicker/blob/master/addon/components/date-picker.js#L174