Provide docker images for the samples

[camilamacedo86]

Description
Instead of we have REPLACE_IMAGE in the samples we could have the docker images which should be used with. Also, these images should be changed/tagged and pushed after each release/sample upgrade.

PS.: I think that would be helpful impl first #86

[estroz]

This is a possibility especially if we get CI running for this repo; we could build a new image on every commit and release.

@hasbro17 wdyt about hosting this in quay.io/operator-framework?

[camilamacedo86]

HI @estroz this is exactly my idea.

We just need a docker/quayio operator-sdk or operator-framework account and do as it is done here in my personal projec: https://github.com/dev4devs-com/postgresql-operator/blob/master/.circleci/config.yml#L26 . Also see here the makefile targets to build and push the images. We can create a tag after each SDK release update. WDYT?

[camilamacedo86]

Closing this one since because we decided to make a proposal with the suggestions for this repo. I will add this topic as well.