Merge branch 'add/buster' into 'master'

Add buster build

See merge request !4
4 jobs for master in 7 minutes and 15 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Test Pre Build
passed #5618
test_build_script

00:01:34

 
  Build
passed #5619
build_nginx_buster

00:03:46

passed #5621
build_nginx_jessie

00:05:41

passed #5620
build_nginx_stretch

00:05:06