- switch to server side processing to retrieve network hosts
  (the table started to be bigger and takes time to load)
- add full text search using elasticsearch

Note that only the first IP is displayed in the host table (all
interfaces were displayed before). Search can be performed on any
interfaces.

JIRA INFRA-595 #action In Progress

JIRA INFRA-575 #action In Progress

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

https://black.readthedocs.io/en/stable/

Fixes INFRA-197

Allow to keep track of batches of small parts.

Column not visible but searchable.
Allow to search comments and TAG number for items imported from JIRA.

Required to create users when importing items from JIRA.

Renamed blueprint from "users" to "user" to be consistent with other
blueprints (inventory and network).

+ fix tests

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/