[fix] Encrypt password and make it safely editable

When the Pull-Request is merged, you have to run these commands to update your database schema and to ensure everything is ok:

    # 1. Remove all databases, re-create them and migrate current
         environment's database (default is development)
    # 2. Migrate test database
    # 3. Run tests

    rake db:drop:all && rake db:create:all && rake db:migrate
    rake db:migrate RAILS_ENV=test
    rspec spec