Refactor: When using an 'around' hook, 'subject' is not available

We need to create an instance of the `described_class` to create our own subject
for the purposes of the hook.

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Change-Id:     I251e1e159e2a7690ce157c2be04eaf86e9617bb6
Signed-off-by: Jeff Felchner <accounts+git@thekompanee.com>
Refactor: Convert 'mock_auth' to an 'around' hook

We need to make sure we clean up after ourselves and remove the method that we
add.

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Change-Id:     I82ac4fad99f160387ec33096fa8eb56ba2b38f08
Signed-off-by: Jeff Felchner <accounts+git@thekompanee.com>
Bugfix: Remove added method from the controller class after spec is run

Previously we were adding the method to the class which meant that, since
constants are not cleaned up after each test run, that method was always there
once it had been added by any test marked with 'mock_auth'.  This caused
intermittent failures.

Now we remove the method after the spec is run

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Change-Id:     I46752844f6669579377ca266fda04c7a64d493c9
Signed-off-by: Jeff Felchner <accounts+git@thekompanee.com>
Style: Make whitespace changes
Version Bump to 0.41.0