Hydropandas

What's Changed
* Update plots.py by HMEUW in https://github.com/ArtesiaWater/hydropandas/pull/98
* Reorganize things a bit by dbrakenhoff in https://github.com/ArtesiaWater/hydropandas/pull/101
* Prevent runtime error, with mulitple bro id's by Florisklooster in https://github.com/ArtesiaWater/hydropandas/pull/107
* Interpolate ObsCollection by martinvonk in https://github.com/ArtesiaWater/hydropandas/pull/109
* Move to pyproject.toml and update testing routine by martinvonk in https://github.com/ArtesiaWater/hydropandas/pull/111
* Update master to v0.7.2 by martinvonk in https://github.com/ArtesiaWater/hydropandas/pull/112

New Contributors
* HMEUW made their first contribution in https://github.com/ArtesiaWater/hydropandas/pull/98
* Florisklooster made their first contribution in https://github.com/ArtesiaWater/hydropandas/pull/107

**Full Changelog**: https://github.com/ArtesiaWater/hydropandas/compare/v0.7.1...v0.7.2

What's Changed
* Bug fix for BRO by OnnoEbbens in https://github.com/ArtesiaWater/hydropandas/pull/100


**Full Changelog**: https://github.com/ArtesiaWater/hydropandas/compare/v0.7.0...v0.7.1

What's Changed
* Update to version 0.7.0 by OnnoEbbens in https://github.com/ArtesiaWater/hydropandas/pull/88
* some small fixes by OnnoEbbens in https://github.com/ArtesiaWater/hydropandas/pull/91


**Full Changelog**: https://github.com/ArtesiaWater/hydropandas/compare/v0.6.1...v0.7.0

What's Changed
* 79 add optional dependencies by martinvonk in https://github.com/ArtesiaWater/hydropandas/pull/80
* update to 0.6.1 by OnnoEbbens in https://github.com/ArtesiaWater/hydropandas/pull/81


**Full Changelog**: https://github.com/ArtesiaWater/hydropandas/compare/v0.6.0...v0.6.1

New features:
- get different types of evaporation from measurements (Pennman, Makkink or Hargraves)
- get an evaporation time series which is interpolated from the time series of multiple measurements stations
- write an ObsCollection to an .xlsx file with one overview tab and another tab per observation
- merge two observations and merge two observation collections.

Some unused modules are removed together with their data and tests. These modules are:
- io_arctic
- io_pystore

Now, the recommended way to store and load an ObsCollection uses pickles:
`ObsCollection.to_pickle('oc.pklz')`

Reading can be done using:

import pandas as pd
oc = pd.read_pickle('oc.pklz')


The knmi module is modified to distinguish between precipitation and meteo stations as described in 70.