Storing email and password locally

[kratsg]

Encryption can be done if the user provides a key to unencrypt as well. This shouldn't be too hard.

• http://www.codebeerstartups.com/2013/04/how-to-encrypt-and-decrypt-data-in-ruby-on-rails
• http://www.brentsowers.com/2007/12/aes-encryption-and-decryption-in-ruby.html