Install gnuplot on Fedora and FreeBSD

3 jobs for !68 with mnowak/add-stress-test-to-CI in 9 minutes and 28 seconds (queued for 2 seconds)
detached
Status Job ID Name Coverage
  Images
passed #990549
amd64 linux docker
fedora:32:amd64:docker

00:04:25

passed #990550
amd64 linux docker
freebsd:11.4:amd64:packer

00:08:40

passed #990551
amd64 linux docker
freebsd:12.1:amd64:packer

00:09:27