Use Heroku image for deploy stage

3 jobs for master in 1 minute and 5 seconds (queued for 1 second)
Status Job ID Name Coverage
  Compile
passed compile #497055

00:00:37

 
  Test
passed test #497056

00:00:24

 
  Deploy
failed deploy #497057

00:00:03

 
Name Stage Failure
failed
deploy Deploy There has been a runner system failure, please try again
Running with gitlab-runner 13.8.0 (775dd39d)
on swamphen.doc.ic.ac.uk qxG51qtz
Preparing the "docker+machine" executor
Using Docker executor with image heroku/heroku:latest ...
Pulling docker image heroku/heroku:latest ...
WARNING: Failed to pull image with policy "always": Error response from daemon: manifest for heroku/heroku:latest not found: manifest unknown: manifest unknown (docker.go:147:1s)
ERROR: Job failed (system failure): failed to pull image "heroku/heroku:latest" with specified policies [always]: Error response from daemon: manifest for heroku/heroku:latest not found: manifest unknown: manifest unknown (docker.go:147:1s)