Move from Travis to GitHub Actions

[ErikBjare]

Needed before we can turn off Travis:

Checklist moved to #106

Closes #106

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (master@214ff66). Click here to learn what that means.
The diff coverage is 87.50%.

@@            Coverage Diff            @@
##             master     #105   +/-   ##
=========================================
  Coverage          ?   66.78%           
=========================================
  Files             ?       48           
  Lines             ?     5769           
  Branches          ?        0           
=========================================
  Hits              ?     3853           
  Misses            ?     1916           
  Partials          ?        0           

Impacted Files	Coverage Δ
aw-client-rust/tests/test.rs	88.52% <0.00%> (ø)
aw-models/src/event.rs	90.62% <100.00%> (ø)
aw-models/src/timeinterval.rs	79.31% <100.00%> (ø)
aw-query/src/functions.rs	90.34% <100.00%> (ø)
aw-transform/src/classify.rs	95.41% <100.00%> (ø)
aw-server/tests/macros.rs	100.00% <0.00%> (ø)
aw-transform/src/sort.rs	100.00% <0.00%> (ø)
aw-server/tests/api.rs	95.68% <0.00%> (ø)
... and 43 more

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[ErikBjare]

Yay, coverage is working! Took forever though (18min).

[ErikBjare]

Since this is such a major improvement to the CI process I'm just going ahead and merging this.