update Facebook post route to return 422 instead of timing out if fb profile has no email

[joelebeau1]

Also, I added the "gulp": "gulp" script to the package.json file because I was unable to run gulp directly by running gulp dist in my terminal after installing all node modules and explicitly installing and confirming installation of gulp package. I figure that since I've never used/downloaded/installed gulp before on my local machine, the same problem would occur if someone were to reproduce my steps on a new computer in the future, so I left the npm script in there to allow npm run gulp dist to be run, which executes without error on my machine.