pin mpl to 3.4.1

[codecov[bot]]

Codecov Report

Merging #306 (3a0c373) into master (4b06e8f) will decrease coverage by 10.8%. The diff coverage is n/a.

@@            Coverage Diff            @@
##           master    #306      +/-   ##
=========================================
- Coverage    79.9%   69.1%   -10.8%     
=========================================
  Files          14      14              
  Lines        1195    1195              
=========================================
- Hits          955     826     -129     
- Misses        240     369     +129     

Impacted Files	Coverage Δ
geosnap/io/storage.py	28.1% <0.0%> (-64.4%)	:arrow_down:
geosnap/analyze/dynamics.py	61.3% <0.0%> (-38.7%)	:arrow_down:
geosnap/_data.py	70.6% <0.0%> (-2.8%)	:arrow_down:
geosnap/_community.py	73.0% <0.0%> (-2.5%)	:arrow_down:

[knaaptime]

the root of this issue has actually been resolved upstream in proplot, but the CI still isnt passing for some reason?

[knaaptime]

the issue is resolved with https://github.com/lukelbd/proplot/pull/268, and can be fixed on our end by pinning to the latest proplot once version 0.8.0 is released