Adds VCS for Gitlab

[bshore]

From tilt-dev/tilt#5909 (comment) - mentions that gitlab.com host/regex is missing.

After this PR, a version bump to v0.2.3 and updating it in tilt-dev/tilt should resolve the original issue

Testing from tilt-dev/tilt

With this branch checked out, in your go.mod replace go-get with a local path

module github.com/tilt-dev/tilt

go 1.19

replace github.com/tilt-dev/go-get => /path/to/this/local/go-get

require (
  // all of the things
)

Run a go mod vendor and then make install

Sample Tiltfile

extension_path="https://gitlab.com/nicks6/tilt-extension-experiment"
v1alpha1.extension_repo(name='tilt-extension-experiment', url=extension_path, ref='main')
v1alpha1.extension(name='tilt_extension', repo_name='tilt-extension-experiment', repo_path='tilt_extension')
load('ext://tilt_extension', 'vue_build', 'dotnet_build')

vue_build("test")
test_yaml = blob("""---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: test
  labels:
    app.kubernetes.io/name: test
spec:
  selector:
    matchLabels:
      app.kubernetes.io/name: test
  template:
    metadata:
      labels:
        app.kubernetes.io/name: test
    spec:
      containers:
        - name: test
          image: test:latest
""")
k8s_yaml(test_yaml)

"$(go env GOPATH)/bin/tilt" up should find and download the gitlab extension, run vue_build("test") and start a container

[nicks]

thanks!