Pass ?qrcode=true as query string

Fix default button issue on login page

- use same postgres container for dev and test
  (create 2 different databases)
- use docker-compose.override.yml to avoid duplication
- ignore more files not needed in the docker image

By default docker-compose reads both docker-compose.yml and
docker-compose.override.yml.
In docker-compose.override.yml we mount the current directory as
a volume for development.

To test the image we only use docker-compose.yml:
- don't force port 5432 to the outside world to avoid conflict
- do not mount the current directory

- change label (jenkins-slave should have docker-compose installed)
- only push when the current commit is a tag

Can use:

  -  /api/items?serial_number=123456
  -  /api/items?location_id=1

This allows a client to login only once a day.

We might want to decrease that and look into refresh token.
But this looks overkill for our use case.

- add more tests
- patching an item update children location and status
- setting the parent on an item updates the location and status with the
  parent ones

This can be done via the Admin interface but this latter shall be
restricted to admin users. This simple page allows the group "create"
to easily add new Manufacturer, Model or Location.

To make it easier, different decorators are created
depending if the user logged in using a JWT (API)
or cookie (web UI).

Clean code at te same time.
The macro from flask-bootstrap already takes care of everything.

- update flask-bootstrap
- update datatables to v1.10.15 for bootstrap 4 support

The CIText type is not known by Flask-Admin and was not rendered.
A custom model converter is required.

See https://github.com/flask-admin/flask-admin/issues/1196

The serial number might not be unique and can't be used
as the string to hash.
There are for example SD cards that all have the same SN.

Using an ICS id allows to pre-print labels that can be assigned to
hardware when scanning serial numbers.
This id shall be easy to remember (unlike UUID).

Most items won't have a name.
hostname could be added in a separate table if required.

Put under the functional directory all tests that require
access to the database. There is a "session" fixture in that
directory that is automatically invoked for each tests. It rollbacks
any transaction after the test to leave the database clean.

Other tests should go under the unit directory.

Inspired from:
- https://stackoverflow.com/a/38626139
- http://alexmic.net/flask-sqlalchemy-pytest/

User and Group shall not be created locally.
They all come from the LDAP/AD server.

Allow to easily pass config for testing

- add build instruction to docker-compose.yml

The citext module provides a case-insensitive character string type.
Use CIText for QRCodeMixin name column.
name should be case-insensitive to avoid duplicate names.