Confidant web interface should indicate if USE_ENCRYPTION=False

[woodrow]

We should show a warning header/banner if you've intentionally disabled encryption (for e.g. in development or trying out Confidant via Docker).

An example from Stripe's OAuth flow (though Confidant's should be more alarming and explicit about the lack of encryption):

[jeff-abe-98]

I would like to work on this but I am having trouble getting started, can someone point me in the right direction?

[ryan-lane]

Hey @jewishjeff. The easiest way to handle this would be to expose some settings through a flask endpoint and have the angularjs app load those settings on initial load. Based on a setting you'd be able to ngHide/ngShow a div in the interface for this.