Clean up Devise Locale Config

[lomky]

We should standardize our Devise wording either into separate files, or included in the base locale file, but not both.

Originally posted by @lomky in #1633 (comment)

[lomky]

See i18n devise project:

https://github.com/plataformatec/devise/wiki/I18n
https://github.com/tigrish/devise-i18n/blob/master/rails/locales/es.yml

[colinxfleming]

Let's please go with separate file if we can, and vendor as much as possible!

[rcackerman]

@colinxfleming I'd be down for working on this! Would using the devise-i18n gem be of interest, or are you trying to limit dependencies?

[colinxfleming]

let's use the devise-i18n gem. So the steps here are:

• install that dependency
• remove the existing devise yml files
• confirm things still work in spanish mode (appending ?locale=es to a url will kick things into spanish mode)