Release tag not being picked up by build

[austinlparker]

While releasing 0.3.0 we discovered that the release tag was not properly being inserted as the image tag (0.3.0 built as 0.1.0) -- this was temporarily worked around by updating the .env file, but it worked correctly for 0.2.0, so something here needs investigation.

[wph95]

https://docs.docker.com/compose/environment-variables/

Values in the shell take precedence over those specified in the .env file.

yeah it's very strange