Improve script to check used source versions

* rename version_check.py to version-check.py
* move requirement beautifulsoup4 from requirements to test-requirements
* add new requirement PrettyTable to test-requirements
* add debug logging messages (can be enabled with --debug parameter)
* add support to load configured versions from a kolla-build.conf
  file (can be used with --config-file parameter)
* use PrettyTable to print out a nice result table

---snip---
+---------+-----------------+----------------+------------------...
| Project | Current version | Latest version | Comparing changes...
+---------+-----------------+----------------+------------------...
| aodh    | 2.0.3           | 2.0.4          | https://github.co...
| cinder  | 8.0.0           | 8.1.0          | https://github.co...
| ironic  | 5.1.1           | 5.1.2          | https://github.co...
| murano  | 2.0.0           | 2.0.1          | https://github.co...
| nova    | 13.1.0          | 13.1.1         | https://github.co...
+---------+-----------------+----------------+------------------...
---snap---

TrivialFix

Change-Id: I5b5d3db34396b2fc95714273612563ea14e78cf8