…1389)

Everything switched to triple mustache in #824 except for these two
occurrences.

Touches all files in the project. Might create merge conflicts for others.

…1391)

* Require Cors header values to be specified with double quotes.

* Fix broken tests

* Code formatting

* Use startswith and endswith.

* Adjust excpetion message and add unit tests to assert exception is thrown

* format using black

* chore: Handle pylint warnings

* fail pytest on warnings

…d in failure (#1410)