Update gitlab ci file

1 job from master in 40 seconds (queued for 8 minutes 51 seconds)
Status Job ID Name Coverage
  Deploy
failed #4
test
docker-deploy

00:40

 
Deploy docker-deploy
 http://ca540913.m.daocloud.io/
Live Restore Enabled: false

WARNING: No swap limit support
$ docker build -t testweb .
Sending build context to Docker daemon 45.57kB
Step 1/6 : FROM flask:latest
pull access denied for flask, repository does not exist or may require 'docker login'
ERROR: Job failed: exit code 1