Merge pull request #2 from ohmage/weeklyDigest

Weekly digest with whenever scheduler
Messages API, mission setting, some authentication improvements
Mergify! (And comment out weekly updates until ready with the new e-mail template for them.)
Peapod scraper; changing protect_from_forgery to not throw exceptions
Update homepage to remove household_size field
Fix delayed e-mail delivery bug for on boarding e-mail
Update e-mail and URL constants for staging server
Update URL paths for mailers
Fix user setting in e-mail processor
Incorporate designs for account confirmation e-mail, mission_and_household_setting e-mail, & getting started email; build hook to send out mission_and_household_setting e-mail after first purchase is scraped
message confirmation email setup