Switch to versioneer

[mraspaud]

This PR switches version management to versioneer.

• Tests passed
• Passes git diff origin/master **/*py | flake8 --diff

[coveralls]

Coverage increased (+0.5%) to 85.788% when pulling 682e17e on mraspaud:feature-versioneer into 86659c3 on pytroll:master.

[codecov]

Codecov Report

Merging #150 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #150      +/-   ##
==========================================
+ Coverage   85.78%   85.78%   +<.01%     
==========================================
  Files          35       34       -1     
  Lines        6212     6213       +1     
==========================================
+ Hits         5329     5330       +1     
  Misses        883      883

Impacted Files	Coverage Δ
pyresample/__init__.py	100% <100%> (ø)	⬆️

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