Ansible-cmdb

Changes in this release:

- Minor bugfixes
- `--exclude-cols` option didn't work in html_fancy template. Fixed.
- "Show only given columns" (`-c` / `--columns` option) now does what you'd think for html_fancy templates.
- Changed the build system from Make to sla.

This release of ansible features the following changes:

* You can now limit which hosts are included in the output with the `-l` / `--limit` commandline option.
* You can now easily add custom columns using the `-C` / `--cust-cols` option. See [the documentation](https://ansible-cmdb.readthedocs.io/en/latest/usage/custom-columns) for how to use them.
* SELinux info is now properly displayed in host details.
* Various minor fixes to templates.
* Support for RPM packages has been dropped due to Alien no longer working properly.

* Better host fact updating prevents problems with differently structured host facts.
* Various improvements and fixes for abnormal network interface structures.

Additionally, support for RPM distribution has been dropped and the Arch Linux instructions have been removed since the package is lagging behind by 8 versions.

* Handle empty host var files properly.
* Fixed free disk space in sql template.
* YAML tags (e.g. `!vault`) in host and group var files are now properly ignored and no longer generate warnings.

This release fixes bugs in the Python package for ansible-cmdb. No other changes were made.

The following features were added or improved:

* Custom and host local facts are now sorted by name
* Updates in the python packages that ansible-cmdb depends on.
* Improvements to the uninstall procedures.

The following bug fixes were made:

* Fixes in how columns are displayed
* Fixes in how custom and host local facts are parsed and displayed.
* Fixes in the markdown template that prevented rendering if there were no host vars.
* Various fixes in the html_fancy templates
* Several fixes that prevented ansible-cmdb from properly working on systems with only Python v3.x
* Bug fix in the RPM package that prevented installation on some Redhat / Centos versions.