Unset env vars passed to `run` via command line options take the
value of the system's var with the same name.
Signed-off-by: Joffrey F <joffrey@docker.com>
The 'env_file' directive and feature precludes the use of the name
'.env' in the path shared with 'docker-config.yml', regardless of
whether or not it is enabled.
This change adds an additional validation to allow the use of this
path provided it is not a file.
Signed-off-by: Thom Linton <thom.linton@gmail.com>
Joffrey F