Step 6 : RUN apt-get -qq update && apt-get -y upgrade
---> Running in d5d22373b15a
W: The repository 'http://security.ubuntu.com/ubuntu xenial-security Release' does not have a Release file.
W: The repository 'http://archive.ubuntu.com/ubuntu xenial Release' does not have a Release file.
W: The repository 'http://archive.ubuntu.com/ubuntu xenial-updates Release' does not have a Release file.
W: The repository 'http://archive.ubuntu.com/ubuntu xenial-backports Release' does not have a Release file.
E: Failed to fetch http://security.ubuntu.com/ubuntu/dists/xenial-security/universe/source/Sources 403 Forbidden [IP: 91.189.88.162 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-backports/restricted/binary-amd64/Packages 403 Forbidden [IP: 91.189.88.161 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial/universe/source/Sources 403 Forbidden [IP: 91.189.88.161 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-updates/universe/source/Sources 403 Forbidden [IP: 91.189.88.161 80]
E: Some index files failed to download. They have been ignored, or old ones used instead.