The `AdminFactory` had a bug: `is_admin` is not a field, but
`is_superuser` is.

No tests were using the factory so this went unnoticed, but I'm about to
want to use it.

chore: gitignore .mo files

Closes #2720

Add .editorconfig

Editorconfig is a standard that helps editors know what whitespace rules
to follow for a given project.

For more information, see:

https://editorconfig.org/

These rules were determined based on feedback from project maintainers.

There are some files that use different numbers of spaces, but these
files were imposed on the project externally.  We use 4 everywhere we
touch.

Issue #2716

Ensure errors are on top

In certain cases validation errors could be hidden by components that
were rendered "on top" (e.g. in the case of required rich text fields).

Providing a z-index signals that they belong on top.

Issue #2718

Add Finance flow fixes and notifications

Upgrade jest to latest version

Parse locale for currency lookup with dash separator

Correctly validate Slack field as optional

Closes #2714

Add Finance 1 and Finance 2 Flow

Add django-fsm for invoice status transition

Update to latest django-hijack and remove loading of removed hijack-styles.css

Update to Django 2.2.27.

Update node packages.