Apply black new stable release (22.1.0)

[dnerini]

Black has finally issued its first stable release. This PR applies it to the whole master branch.

[codecov]

Codecov Report

Merging #261 (be1682d) into master (5f162d4) will not change coverage.
The diff coverage is 65.00%.

@@           Coverage Diff           @@
##           master     #261   +/-   ##
=======================================
  Coverage   80.92%   80.92%           
=======================================
  Files         142      142           
  Lines       10758    10758           
=======================================
  Hits         8706     8706           
  Misses       2052     2052           

Flag	Coverage Δ
unit_tests	80.92% <65.00%> (ø)

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Impacted Files	Coverage Δ
pysteps/datasets.py	38.69% <0.00%> (ø)
pysteps/noise/fftgenerators.py	69.32% <0.00%> (ø)
pysteps/scripts/fit_vel_pert_params.py	0.00% <ø> (ø)
pysteps/scripts/run_vel_pert_analysis.py	0.00% <0.00%> (ø)
pysteps/timeseries/autoregression.py	85.80% <ø> (ø)
pysteps/visualization/spectral.py	16.66% <0.00%> (ø)
pysteps/nowcasts/anvil.py	69.49% <50.00%> (ø)
pysteps/cascade/bandpass_filters.py	92.22% <100.00%> (ø)
pysteps/downscaling/rainfarm.py	100.00% <100.00%> (ø)
pysteps/nowcasts/lagrangian_probability.py	100.00% <100.00%> (ø)
... and 7 more

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