Require image for ARM64 architecture

[odidev]

Hi team,

I am trying to use arbourd/concourse-slack-alert-resource on ARM64 architecture but it seems the arm64 tag is not available in Docker Hub.

I have successfully built the image using the command docker build -t <image_name> . on arm64 platform without any changes.

I have used buildx in Github actions to build and push the image for both platforms.

Commit Link - odidev@d28ff39

Github actions Link - https://github.com/odidev/concourse-slack-alert-resource/runs/1820414170?check_suite_focus=true

Dockerhub Link - https://hub.docker.com/repository/docker/odidev/concourse-slack-alert-resource

Please share your opinion on this. If interested, I will raise a PR.

[arbourd]

Ya, moving away from Docker Hub for builds is probably a good idea. I will accept a Github Actions PR. I will need to edit it a bunch, but we could get it in soon. Thanks!

[odidev]

I have raised a PR.

PR Link - #75

[arbourd]

Released with v0.14.1