Merge branch 'add/buster' into 'master'

Add buster image

See merge request !8
12 jobs for master in 1 minute and 53 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  Test
passed #2504
lint-dockerfile

00:01:53

passed #2505
lint-shell-script

00:01:46

 
  Deploy
manual #2507
allowed to fail manual
build-debian-buster-build-master
manual #2509
allowed to fail manual
build-debian-jessie-build-master
manual #2508
allowed to fail manual
build-debian-stretch-build-master
manual #2506
allowed to fail manual
build-golang-master
manual #2515
allowed to fail manual
build-php-5.3-master
manual #2514
allowed to fail manual
build-php-5.6-master
manual #2513
allowed to fail manual
build-php-7.0-master
manual #2512
allowed to fail manual
build-php-7.1-master
manual #2511
allowed to fail manual
build-php-7.2-master
manual #2510
allowed to fail manual
build-php-7.3-master