Django 2.2 and template changes to reflect IETF 108

This release moves the codebase to Django 2.2 and updates the template for email sent when a match is made to match IETF108's conditions.

With the upgrade to Django 2.2, sqlite3 based testing fails. Tests run on mysql (which matches production) succeed. See issue #25.

Update match template signature line, limit remote attendance responses to Yes or No

Update match template signature line, limit remote attendance responses to Yes or No

Handle remote participants

Collect whether participants will be remote and whether guides are willing to guide remote participants.

Be more forgiving with date formats

Allow dashes as well as slashes while interpreting input dates

Cancelling matches before email is sent

Add the ability to cancel a match from the match email view

Addresses containerization and Python port issues

Addresses containerization and Python port issues

IETF 105 specific template changes

Changes to email templates for IETF 105.

Operational Improvements

Reworked startup to use an already built mod_wsgi-express generated config.
Moved mod_wsgi-express generated config out to the host filesystem.
Added several packages to assist with operations.
Added a script to regenerate the mod_wsgi-express configuration in a comparison directory.

Conversion to Python 3

v0.9.1

Merge branch 'master' of https://github.com/ietf-tools/ietf-guides