Auth by username instead of email

Added username to User table/model

spec/factories/users.rb

@@ -1,5 +1,6 @@
 FactoryGirl.define do
   factory :user do
+    sequence(:username) { |n| "user_#{n}" }
     sequence(:email) { |n| "user_#{n}@example.com" }
     password 'password'
     password_confirmation { password }
@@ -9,16 +10,19 @@ FactoryGirl.define do
     association :user_role, factory: :role_user
 
     factory :staff do
+      username "staff"
       first_name 'Staff'
       association :user_role, factory: :role_staff
     end
 
     factory :admin do
+      username "admin"
       first_name 'Admin'
       association :user_role, factory: :role_admin
     end
 
     factory :bike_admin do
+      username "bike_admin"
       first_name 'BikeAdmin'
       association :user_role, factory: :role_bike_admin
     end