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.

application.py

@@ -1,38 +1,10 @@
-#!/usr/bin/env python
-
+##!/usr/bin/env python
 from __future__ import print_function
-import os
-from flask_script import Manager, Server
-from flask_migrate import Migrate, MigrateCommand
-from app import (create_app, db, commands)
 
-application = create_app()
-manager = Manager(application)
-port = int(os.environ.get('PORT', 6011))
-manager.add_command("runserver", Server(host='0.0.0.0', port=port))
+from flask import Flask
 
-migrate = Migrate(application, db)
-manager.add_command('db', MigrateCommand)
-manager.add_command('create_provider_rate', commands.CreateProviderRateCommand)
-manager.add_command('purge_functional_test_data', commands.PurgeFunctionalTestDataCommand)
-manager.add_command('custom_db_script', commands.CustomDbScript)
-manager.add_command('populate_monthly_billing', commands.PopulateMonthlyBilling)
-manager.add_command('backfill_processing_time', commands.BackfillProcessingTime)
-manager.add_command('populate_service_email_reply_to', commands.PopulateServiceEmailReplyTo)
-manager.add_command('populate_service_sms_sender', commands.PopulateServiceSmsSender)
-manager.add_command('populate_service_letter_contact', commands.PopulateServiceLetterContact)
-manager.add_command('populate_service_and_service_history_free_sms_fragment_limit',
-                    commands.PopulateServiceAndServiceHistoryFreeSmsFragmentLimit)
-manager.add_command('populate_annual_billing', commands.PopulateAnnualBilling)
-manager.add_command('rerun_build_dvla_file', commands.ReRunBuildDvlaFileForJob)
+from app import create_app
 
+app = Flask('app')
 
-@manager.command
-def list_routes():
-    """List URLs of all application routes."""
-    for rule in sorted(application.url_map.iter_rules(), key=lambda r: r.rule):
-        print("{:10} {}".format(", ".join(rule.methods - set(['OPTIONS', 'HEAD'])), rule.rule))
-
-
-if __name__ == '__main__':
-    manager.run()
+create_app(app)