Make some changes to DealHunter

[billytran1222]

• [x] Add authentication Note: we want to disable the sign up function. This is an invite-only site. We'll create username and password on our end only.
• [x] Adjust the "Hot Deal?" criteria. The new formula is if Price <= .75 x min(Comps, Zestimate)
• [x] Add a "Display hot deals only" checkbox for the view
• [x] Add "Sq Ft" to the table view
• [x] Do some tests to make sure the email won't go to SPAM folder