Solo-epd-loader

<!-- Release notes generated using configuration in .github/release.yml at v0.3.4 -->

What's Changed
- Make `resample_df` independent of seppy
- Add test functions & corresponding GitHub Actions
- Remove 3.6 & 3.7 from supported Python versions because they're not srupported by sunpy any more
- Clean requirements (hopefully fix 17 for conda-forge)

**Full Changelog**: https://github.com/jgieseler/solo-epd-loader/compare/v0.3.3...v0.3.4

<!-- Release notes generated using configuration in .github/release.yml at v0.3.3 -->

What's Changed
- Bugfix circular import caused by adding function `resample_df` from [seppy](https://github.com/serpentine-h2020/SEPpy)

**Full Changelog**: https://github.com/jgieseler/solo-epd-loader/compare/v0.3.2...v0.3.3

<!-- Release notes generated using configuration in .github/release.yml at v0.3.2 -->

What's Changed
- Add function `combine_channels` to combine fluxes of multiple adjacent energy channels of EPT or HET (fix 13)
- Obtain resampling function `resample_df` from [seppy](https://github.com/serpentine-h2020/SEPpy) (fix #18)

**Full Changelog**: https://github.com/jgieseler/solo-epd-loader/compare/v0.3.1...v0.3.2

<!-- Release notes generated using configuration in .github/release.yml at v0.3.1 -->

What's Changed
- Add omni-directional data (`viewing='omni'`) for loading EPT and HET data (https://github.com/jgieseler/solo-epd-loader/commit/1d26657757ab649369cf6746b8d955e6d2682816). This loads all four viewing directions and calculates an average of those following `('sun'+'asun'+'north'+'south')/4`
- Add tqdm progress bar to `calc_electron` (https://github.com/jgieseler/solo-epd-loader/commit/5599880d1a6cab2a9c1e987c1c82d9bc74adea10)
- Catch error when loading empty STEP data (https://github.com/jgieseler/solo-epd-loader/commit/ddc14cfacffc78ca1dde9287c406009cd0405fba)

**Full Changelog**: https://github.com/jgieseler/solo-epd-loader/compare/v0.3.0...v0.3.1

<!-- Release notes generated using configuration in .github/release.yml at v0.2.8 -->

What's Changed
- STEP data loading rewritten. Now all STEP data is supported (fix 23)! Some unused data (e.g. counting rates) is skipped in the loading, which should result in less memory-consumption (and a little speed-up).
- Returns all STEP data as normal-indexed DataFrame (previously only for new STEP data product; somehow fixes 9).
**Careful: This means the data is returned in a slightly different format; you might need to adjust your code!**
You can try to use the new helper function `create_multiindex` after obtaining the new DataFrame `df` to get a similar multiindexed DataFrame as before for the old STEP data product:
python
>>> from solo_epd_loader import epd_load, create_multiindex
>>> df, energies = epd_load(sensor='step', startdate=20220403, autodownload=True)
>>> df = create_multiindex(df)
>>> df.head()
DELTA_EPOCH Integral_Avg_Flux ... Magnet_Avg_Uncertainty QUALITY_BITMASK QUALITY_FLAG SMALL_PIXELS_FLAG
DELTA_EPOCH Integral_Avg_Flux_0 Integral_Avg_Flux_1 Integral_Avg_Flux_2 ... Magnet_Avg_Uncertainty_31 QUALITY_BITMASK QUALITY_FLAG SMALL_PIXELS_FLAG
Time ...
2022-04-03 00:00:00.396785 1.0 423233152.0 266092544.0 167752016.0 ... 0.000000 18.0 1.0 0.0
2022-04-03 00:00:01.396787 1.0 400162176.0 262457408.0 186587328.0 ... 0.000000 18.0 1.0 0.0
2022-04-03 00:00:02.396789 1.0 388228896.0 260276320.0 170106416.0 ... 0.000000 18.0 1.0 0.0
2022-04-03 00:00:03.396791 1.0 361180160.0 242100592.0 161865968.0 ... 0.000000 18.0 1.0 0.0
2022-04-03 00:00:04.396792 1.0 372317888.0 255187120.0 167752016.0 ... 24368.373047 18.0 1.0 0.0

[5 rows x 132 columns]


- Make compatible to cdflib 1.0 (fix 27)


**Full Changelog**: https://github.com/jgieseler/solo-epd-loader/compare/v0.2.8...v0.3.0

<!-- Release notes generated using configuration in .github/release.yml at v0.2.8 -->

What's Changed
Bugfixes 🛠
* Remove bug introduced by changes in 0.2.7


**Full Changelog**: https://github.com/jgieseler/solo-epd-loader/compare/v0.2.7...v0.2.8