Remove deprecated ActiveSupport::Deprecation singleton

[jpteti]

Using ActiveSupport::Deprecation directly has itself been deprecated in favor of storing an instance of it in your own gem.

I’ve given a try to fixing this in the simplest way possible as described in the docs. I updated the existing tests (which are passing for me) but have not written new ones. (The only one I can think of is for the Railtie fix?) Hopefully I’m not missing any important points.

[bmt-github-policybot]

This pull request has been automatically closed because it has not been updated in the last 3 months. :sleepy:

If you still need this change, please reopen it and update it within the next 3 months.

Thanks for helping keep our house in order!

[rzane]

Fixed in https://github.com/Betterment/uncruft/pull/38