Relicense to Apache Version 2

[mraspaud]

@pnuu @TAlonglong @adybbroe here comes another one...

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.56%. Comparing base (e1e4f36) to head (c671e5e).
⚠️ Report is 13 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #77   +/-   ##
=======================================
  Coverage   96.56%   96.56%           
=======================================
  Files          13       13           
  Lines         786      786           
=======================================
  Hits          759      759           
  Misses         27       27           

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[TAlonglong]

I approve

[pnuu]

I approve the licence change.

[adybbroe]

I approve

[gerritholl]

Shouldn't this wait until posttroll has had a release with the new license?

[mraspaud]

Shouldn't this wait until posttroll has had a release with the new license?

I don't think it's needed as apache v2 is gplv3-compatible.