Add gitlab ci yaml

1 job from master in 19 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Deploy
failed #1
test
docker-deploy

00:19

 
Deploy docker-deploy
Using docker image sha256:3f53bb00af943dfdf815650be70c0fa7b426e56a66f5e3362b47a129d57d5991 for alpine:latest ...
Running on runner-e75965fe-project-76-concurrent-0 via b56c8aa35a28...
Cloning repository...
Cloning into '/builds/zhengtianbao/cicd'...
Checking out 379a984b as master...
Skipping Git submodules setup
$ docker build -t testweb .
/bin/sh: eval: line 50: docker: not found
ERROR: Job failed: exit code 127