Release of version 0.5.0

…aFrame (#234)

* Update timestamps to be dtype DateTime instead of float by default.

- Updates MetricRangeDataFrame to have pd.DatetimeIndex instead of
  pd.Float64Index.
- Updates MetricSnapshotDataFrame to have the column timestamp as
  dtype datetime64[ns] instead of float64.
- Adds test to ensure correct dtype conversion.

* Rename timestamp (unix time) to datetime parameter in dataframes.

Bumps [pillow](https://github.com/python-pillow/Pillow) from 8.4.0 to 9.0.1.
- [Release notes](https://github.com/python-pillow/Pillow/releases)
- [Changelog](https://github.com/python-pillow/Pillow/blob/main/CHANGES.rst)
- [Commits](python-pillow/Pillow@8.4.0...9.0.1)

---
updated-dependencies:
- dependency-name: pillow
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>

* Casting metric values to a float; Adding a test for it as well;

* Checking for str to convert to float; Adding custom exception;

* Removing unused init param;

* Renaming exception name;

* Adjusting exception check to include ValueError; Updating Exception name; Adding a couple tests;

* Adding a couple validation tests for MetricDataRange as well;

* Fixing some linting issues I missed;

Add github action to run pytest on multiple python versions

Sync with dependencies listed in the Pipfile

* Add get_label_values function in prometheus_connect.py.

* Improving the all_metrics function via get_label_values.

* Added tests for get_label_values().

Co-authored-by: Alexey Sergeev <[email protected]>

Add github action to create pypi releases for github releases

⬆️ Bump pillow from 8.4.0 to 9.0.1

Update version number to `0.5.1`