Update .gitlab-ci.yml to install dpl for deploy phase

3 jobs for master in 46 seconds (queued for 1 second)
Status Job ID Name Coverage
  Compile
passed compile #497026

00:00:20

 
  Test
passed test #497027

00:00:18

 
  Deploy
failed deploy #497028

00:00:07

 
Name Stage Failure
failed
deploy Deploy
Created fresh repository.
Checking out 94b87e83 as master...

Skipping Git submodules setup
Executing "step_script" stage of the job script
/usr/bin/bash: line 107: apt-get: command not found
$ apt-get update -yq
Cleaning up file based variables
ERROR: Job failed: exit code 1