Add a CaptchaEditResult with data about the Captcha

Also adds a test that triggers a Captcha.

Change-Id: Ic5331e2356ceff2b40ef95833305fb407c3392a8
Handle Captchas returned when editing

- Captcha needs to be scaled up. Picasso has an issue with reading
  our captcha images for some reason if we try to resize them:
  https://github.com/square/picasso/issues/249#issuecomment-33259920
  This will need to be worked around

Change-Id: Iadce6af2f1dc66bcf41adc19363ca4d28ce56971