Add login & user tests

spec/factories/contests.rb

@@ -0,0 +1,5 @@
+FactoryBot.define do
+  factory :contest do
+    name { Faker::Company.unique.name }
+  end
+end

spec/factories/users.rb

@@ -1,7 +1,11 @@
 FactoryBot.define do
   factory :user do
-    username { Faker::Internet.username }
-    email_address { Faker::Internet.email }
-    password { Faker::Internet.password(min_length: 12, max_length: 18) }
+    username { Faker::Internet.unique.username }
+    email_address { Faker::Internet.unique.email }
+    password { Faker::Internet.unique.password(min_length: 12, max_length: 18) }
+  end
+
+  trait :admin do
+    admin { true }
   end
 end