feat: pipelines with GitHub Actions

[prlanzarin]

@fcecagno:

Add four pipelines:

• run hadolint in the Dockerfile
• run tests using npm run test
• run trivy in the repository
• build and push the docker image, and run trivy in the built image

Run workflows on PR create/update and tag.

Configuring:

Add the following secrets to the GitHub repo:

REGISTRY_USERNAME
REGISTRY_TOKEN
They are the credentials to be used to push the image to the docker images registry.

Add the following variables to the GitHub repo:

REGISTRY_URI
REGISTRY_ORGANIZATION
Considering the image bigbluebutton/bbb-webhooks:v3.0.0, the value for REGISTRY_URI would be docker.io (URI for DockerHub) and REGISTRY_ORGANIZATION would be bigbluebutton. The image name bbb-webhooks isn't configurable, and the tag will be the GitHub tag OR pr-<pr number>.

[antobinary]

Beautiful! 👏

[fcecagno]

@antobinary please see here the details on what vars and secrets must be set in the repository: https://github.com/mconf/bbb-webhooks/blob/pipeline/.github/workflows/README.md

[prlanzarin]

This has been squashed and manually pushed into develop.