Add login & user tests

spec/support/helpers.rb

@@ -0,0 +1,12 @@
+module Helpers
+  def login(user)
+    visit '/'
+    fill_in "Email address", with: user.email_address
+    fill_in "Password", with: user.password
+    click_button "Sign in"
+  end
+end
+
+RSpec.configure do |c|
+  c.include Helpers
+end