Update calendar export information.
Update calendar export information.

https://github.com/madewithbytes/us_ignite/issues/288

The calendar preserves the timezone of the event created
it also adds relevant information to the ``ics`` file
such as location, description and URL.

us-ignite/us_ignite,us-ignite/us_ignite,us-ignite/us_ignite,us-ignite/us_ignite,us-ignite/us_ignite