Add docker ENV capability

[PierreRambaud]

Reasons:

• Docker doesn't care about environments variables even if we use system files such as /etc/environment or /etc/profile. Otherwise we must use --env-files or --env when running docker with command line.

Changes:

• Add --env (multiple call possible) and --env-files PATH[:PATH] in docker init
• This will add some lines in Dockerfile

Example:
    --env FOO=BAR --env BAZ=BAT
    # Will add
    ENV FOO=BAR
    ENV BAZ=BAT

[PierreRambaud]

Gentle ping :)

[PierreRambaud]

Just seeing the deprecation of this repository, so I close this issue. Regards,