def self.from_omniauth(hash)
    where(provider: hash.provider, uid: hash.uid).first_or_create do |user|
      user.email = hash.info.email
      user.password = Devise.friendly_token[0,20]
      user.username = hash.info.name
end

User Load (25.0ms)  SELECT  "users".* FROM "users" WHERE "users"."provider" = $1 AND "users"."uid" = $2  ORDER BY "users"."id" ASC LIMIT 1  [["provider", "facebook"], ["uid", "879615942106023"]]
   (10.0ms)  BEGIN
User Exists (12.2ms)  SELECT  1 AS one FROM "users" WHERE "users"."email" = 'vinibol12@yahoo.com.br' LIMIT 1
  SQL (12.7ms)  INSERT INTO "users" ("provider", "uid", "email", "encrypted_password", "username", "created_at", "updated_at") VALUES ($1, $2, $3, $4, $5, $6, $7) RETURNING "id"  [["provider", "facebook"], ["uid", "879615942106023"], ["email", "vinibol12@yahoo.com.br"], ["encrypted_password", "$2a$10$z3oK6H1P5Z0It7VliVw1hehF.Mn1kFlvZbru919lDR.IiHb94Ha/u"], ["username", "Vinicius Antonio Bolzani"], ["created_at", "2015-07-20 08:58:04.227271"], ["updated_at", "2015-07-20 08:58:04.227271"]]
   (2.4ms)  COMMIT