Add Qubes master key

[herypt]

Closes QubesOS/qubes-issues#2544

[codecov]

Codecov Report

Merging #370 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #370   +/-   ##
=======================================
  Coverage   63.97%   63.97%           
=======================================
  Files          51       51           
  Lines        9196     9196           
=======================================
  Hits         5883     5883           
  Misses       3313     3313           

Flag	Coverage Δ
#unittests	63.97% <ø> (ø)

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