[gnome-commander] Dockerfile removed, instead we are now using Gnome GitLab CICD pipelines

[Uwe Scholz <uwescholz src gnome org>]

commit de5994f3df7a6a16b64b0b1a5b073bb21d73b827
Author: Uwe Scholz <u scholz83 gmx de>
Date:   Sun Jan 30 00:03:55 2022 +0100

    Dockerfile removed, instead we are now using Gnome GitLab CICD pipelines
    
    For this, see commit f44836d5.
    
    Also, we remove .travis.yml as this service is not used anymore.

 .travis.yml | 24 ------------------------
 Dockerfile  | 34 ----------------------------------
 2 files changed, 58 deletions(-)