Add github actions from nix-emacs-ci and some small fixes

[snogge]

Looks like the github actions work way better than evm on travis.

[codecov-commenter]

Codecov Report

Merging #27 into master will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##           master      #27   +/-   ##
=======================================
  Coverage   75.28%   75.28%           
=======================================
  Files           1        1           
  Lines         178      178           
=======================================
  Hits          134      134           
  Misses         44       44           

Impacted Files	Coverage Δ
cov.el	75.28% <ø> (ø)

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[AdamNiederer]

Thanks!