Add endpoints:
DELETE /network/hosts/<host_id>
DELETE /network/interfaces/<interface_id>

JIRA INFRA-570 #action In Progress

- set cascade to all and delete-orphan to delete interfaces when
  deleting a host
- button added on the view host page to delete host (admin only)

JIRA INFRA-557 #action In Progress

Retrieving all items from the database takes some time.
The task is thus handled by the RQ worker.
We use ajax to periodically monitor the status of the job
and redirect to the file when ready.
A progress bar is displayed to let the user see the progress.

The mechanism put in place could be re-used for other use cases.

JIRA INFRA-545 #action In Progress

JIRA INFRA-545

Included libraries:
- DataTables 1.10.18 (with bootstrap 4 theme)
- Buttons 1.5.2
- Column visibility 1.5.2
- Print view 1.5.2

JIRA INFRA-545

This was just a typo...
It should be AnsibleGroup instead of AnsibleQuery...

JIRA INFRA-548

ztp_stack can be empty.
We pass it as extra vars only if it's not.
The survey of the AWX_ZTP_CONFIGURATION template shall be updated to set
the ztp_stack parameter as not required.

JIRA INFRA-547

Allow to copy/paste the output of the "ansible-vault encrypt_string"
command to CSEntry

JIRA INFRA-544 #action In Progress

This is not directly supported by CodeMirror.
See https://github.com/codemirror/CodeMirror/issues/850

Add cm-resize library from https://github.com/Sphinxxxx/cm-resize

JIRA INFRA-543 #action In Progress

JIRA INFRA-526

The .git directory is used to identify the release number

WARNING! To pass the SECRET_KEY as en env variable, you should use
base64 encoding as the key is supposed to be a random string of bytes.

Errors are now sent to sentry.
No need to send them directly via e-mail.

JIRA INFRA-525

JIRA INFRA-525 #action In Progress

CSENTRY_ENVIRONMENT shall be set to production|staging|development
It can be used when sending errors to Sentry

JIRA INFRA-525

JIRA INFRA-500 #action In Progress

New feature added in GitLab 11.2.
See https://docs.gitlab.com/ee/ci/yaml/README.html#artifacts-reports-junit

New variable required to generate ZTP configuration.
Note that we can only pass strings with extra_vars in AWX API (no list
or dict).

JIRA INFRA-458 #action In Progress

JIRA INFRA-459 #action In Progress

Updating to 2.2.1 introduced some regressions.
Some fields (vars, hosts) are empty when editing an Ansible group.

Using the latest version probably require some code changes.

Using flask-login request_loader, we can validate jwt tokens.
This allows to use the same decorators for the web UI (using cookies)
and the API (using JWT) as well as the current_user local proxy.

New get_json method on test client response.
See http://flask.pocoo.org/docs/1.0/testing/#testing-json-apis

- requirements-to-freeze.txt is used to list only the needed packages
- requirements.txt is used to build a reproducible environment
- requirements-dev.txt is for testing and building the documentation

The official flask-bootstrap is still not compatible with bootstrap 4.
The application basically only uses the main template and one macro.
It's easier to include directly bootstrap in CSEntry.
It makes upgrading to the latest bootstrap much easier and removes a
dependency.

Update to bootstrap 4.1.3

Added:
- jquery-3.3.1.min.js
- bootstrap.bundle.min.js (include popper but not jquery)

Note that jquery.slim can't be used.
We need for example $.getJSON for datatables.

JIRA INFRA-424