add tests for guest and authenticated shopper checkout and add button for guest checkout

update guest checkout tests
Match guest-checkout styles to site
removed helpers tests for not having content
Remove duplicate tests
Clean up feature tests
- logged in user cannot create items
- logged in user cannot see other users info
- appended file names w/ test
Base setup for contact
Sendgrid set up
Set development mail env to mailcatcher, kept production as Sendgrid.
use prevous fix to fix merge conflict in test_helper
minor fix to test format
added account confirmation email
fix conflicts in views/sessions/new.html.erb and test/featrues/checkout_as_guest.rn
fix merge conflict in test_helper
fix messed up merge in sessions#new view