update containers with OCI labels

[joshmoore]

MAINTAINER command is deprecated. Instead:

LABEL maintainer="..."
LABEL org.opencontainers.image.created="unknown"
LABEL org.opencontainers.image.revision="unknown"
LABEL org.opencontainers.image.source="..."

[joshmoore]

cF.

# Makefile
RELEASE = $(shell date -u +%Y-%m-%dT%H:%M:%SZ)
COMMIT = $(shell git rev-parse HEAD || echo -n NOTGIT)
...
	perl -i -pe 's/(org.opencontainers.image.created=)"([^"]+)"/$$1"$(RELEASE)"/' Dockerfile
	perl -i -pe 's/(org.opencontainers.image.revision=)"([^"]+)"/$$1"$(COMMIT)"/' Dockerfile