[WIP] start segregation dynamics module

[knaaptime]

this PR addresses #77, providing parallelized wrappers around segregation's batch_compute functions. Once merged, geosnap users can quickly examine the ways that segregation has changed in a given region over time (and whether those changes are consistent across spatial scales and dimensions of segregation)

remaining to to:

• [x] add docstrings
• [x] add tests
• [ ] finalize function nomenclature
• [ ] update docs
• [ ] push example notebook

[knaaptime]

when i run tests locally, the new tests pass if I run them independently (e.g. pytest geosnap/tests/test_segdyn.py). But I get a divide by 0 error when running the multigroup_dynamics test (stemming from multidissim) if i run the full test suite (pytest geosnap/tests). No idea why that's happening

[codecov[bot]]

Codecov Report

Merging #307 (56f9c07) into master (e5ddd73) will decrease coverage by 0.6%. The diff coverage is 52.7%.

@@           Coverage Diff            @@
##           master    #307     +/-   ##
========================================
- Coverage    69.1%   68.5%   -0.6%     
========================================
  Files          14      15      +1     
  Lines        1195    1252     +57     
========================================
+ Hits          826     858     +32     
- Misses        369     394     +25     

Impacted Files	Coverage Δ
geosnap/_data.py	70.6% <ø> (ø)
geosnap/analyze/cluster.py	92.7% <ø> (ø)
geosnap/io/util.py	35.1% <4.5%> (-6.1%)	:arrow_down:
geosnap/analyze/segdyn.py	70.2% <70.2%> (ø)
geosnap/__init__.py	100.0% <100.0%> (ø)
geosnap/_community.py	73.0% <100.0%> (ø)
geosnap/analyze/__init__.py	100.0% <100.0%> (ø)
geosnap/io/storage.py	28.1% <100.0%> (ø)