Remove flask-script, move commands to click

click (http://click.pocoo.org/) is used by flask to run its cli args.
In removing flask_script (it's unmaintained), we had to migrate all our
commands to use click. This is a change for the better in my eyes - you
don't need to define the command in several places, and it makes
managing options a bit easier.

View diff with whitespace turned off unless you're a masochist.

README.md

@@ -44,6 +44,9 @@ export FIRETEXT_API_KEY='FIRETEXT_ACTUAL_KEY'
 export STATSD_PREFIX='YOU_OWN_PREFIX'
 export NOTIFICATION_QUEUE_PREFIX='YOUR_OWN_PREFIX'
 export REDIS_URL="redis://localhost:6379/0"
+export FLASK_APP=application.py
+export FLASK_DEBUG=1
+export WERKZEUG_DEBUG_PIN=off
 "> environment.sh
 ```