[License] Move to BSD 3 Clause

Fixes #60
2 jobs for 60_bsd_licensing in 19 minutes and 36 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Build
passed #159801
docker-build
build_linux_36

00:19:35

65.0%
passed #159802
macosx
build_macosx_36

00:18:29

64.0%