Revision 9d1a5dec3f04467db637f4680b3b140603643bff

Committed on 15/12/2017 5:43 am by dennisxrow <dennis@xrow.de> [GitHub Diff]

Clear Composer cache when building a Docker image

Removing the composer cache in case of a Docker build will save up to
300 MB of space inside the image.

The cache won't be used after the build so it's save to remove it.

The .dockerenv file is created by Docker and it's a good way to
determine if we are running inside a Docker container.

See https://support.xrow.net/redmine/public/issues/11670