Update .gitignore to ignore .vscode and .DS_Store files

Closes #53

See merge request !52

Update Node packages to latest versions and fix package version locking

Closes #52

See merge request !51

Replace README text with Guidebook links

Closes #49

See merge request !50

Update Node packages to latest versions, remove yarn.lock (as the build and
test flow doesn't use yarn), and update package-lock.json so it actually
specifies the versions of package dependencies (which causes npm to give more
deterministic results).

Revert "Update README.md"

See merge request !49

This reverts commit 20f4664c

port externalsettings infrastructure from g suite authenticator

Closes #48

See merge request !47

The name of the application in gunicorn should be taken from
cookiecutter's config, not hard-coded :).

Make use of external settings when running tests. We need to specify a
secret key and database configuration as those are required settings.
The boilerplate does not actually have any database models defined so it
is sufficient to provide a "stub" database configuration based on
sqlite.

This is a port of the changes introduced by [1] which allow external
settings to be loaded from URLs, environment variables or the local
filesystem.

[1] https://gitlab.developers.cam.ac.uk/uis/devops/gsuite/g-suite-authenticator/-/merge_requests/2

Closes #48

Update README.md to note CRLF gotcha for Windows users

See merge request !44

Force django 2.2.x

Closes #44

See merge request !43

Backport SMI improvements

Closes #42

See merge request !42

Allow cookiecutting react app to be optional

Closes #41

See merge request !41

Add React frontend and example api

Closes #24

See merge request !40

Port bootstrap improvements from lecture capture preferences webapp

Closes #35

See merge request !36

Remove references to old Github accounts

Closes #38

See merge request !39

The regex used in the test was using a deprecated feature. Remove it.

If X-Forwarded-For headers are not configured, flake8 moans about a
blank line in the generated settings file.

Unless overridden by an environment variable, default to disabling the
HTTP->HTTPS redirect when running tests. This fixes previously broken
tests.

The tox.sh was unused and, in fact, did not work since there was no
./compose.sh in the root directory. This meant that running ./tox.sh on
a local machine would result in an error, not running tests.

On the same note, modify the tox environment to allow for any Python3
version rather than hard-coding 3.7. This would let us test on multiple
Python versions if we decide to.