perf(Cloak.Config.all/0): remove calls to ensure_loaded when checking…

[tomciopp]

… for ciphers

@danielberkompas I noticed a fairly significant slowdown in my test suite (229 => 590 secs) after updating cloak to 0.5.0. I tracked it down to the following lines. (that I myself added) I originally added the ensure_loaded as an additional safety check but it should not be necessary.

On a separate note it may be useful to add a dummy cipher for testing so that we don't actually perform any expensive encrypting or decrypting calls. If you think that is a good idea, I will explore adding it to the codebase.

[danielberkompas]

This looks good. Regarding a dummy cipher, that could be useful for some folks.

Personally, I would want to use the real cipher in test mode to make sure that production won't act any differently, but others might not think the same way.