dashboard: enable email verification

[dbarrosop]

Current situation:

1. We don't require email verifications
2. Users that signed up using email/password have email verified set to false
3. Users that signed up/in using github have email verified set to true

We need to do the following changes to the login workflow:

1. Catch the unverified-user error and:
   1. Let the user know they need to verify the email
   2. Provide a button to send the email verification