Travis build failing on Debian 7

[bourtemb]

The recent Travis builds are all failing on Debian 7:

Step 5/19 : RUN apt-get update && apt-get install -y apt-utils
 ---> Running in 74161e0792e0
Ign http://deb.debian.org wheezy Release.gpg
Ign http://deb.debian.org wheezy-updates Release.gpg
Ign http://deb.debian.org wheezy-backports Release.gpg
Ign http://deb.debian.org wheezy Release
Ign http://deb.debian.org wheezy-updates Release
Ign http://deb.debian.org wheezy-backports Release
Get:1 http://security.debian.org wheezy/updates Release.gpg [1601 B]
Get:2 http://security.debian.org wheezy/updates Release [52.3 kB]
Err http://deb.debian.org wheezy/main amd64 Packages
  404  Not Found
Err http://deb.debian.org wheezy-updates/main amd64 Packages
  404  Not Found
Get:3 http://security.debian.org wheezy/updates/main amd64 Packages [743 kB]
Err http://deb.debian.org wheezy-backports/main amd64 Packages
  404  Not Found
Fetched 797 kB in 0s (931 kB/s)
W: Failed to fetch http://deb.debian.org/debian/dists/wheezy/main/binary-amd64/Packages  404  Not Found
W: Failed to fetch http://deb.debian.org/debian/dists/wheezy-updates/main/binary-amd64/Packages  404  Not Found
W: Failed to fetch http://deb.debian.org/debian/dists/wheezy-backports/main/binary-amd64/Packages  404  Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.
The command '/bin/sh -c apt-get update && apt-get install -y apt-utils' returned a non-zero code: 100
The command "docker build --build-arg APP_UID=$(id -u) --build-arg APP_GID=$(id -g) -t cpp_tango .travis/${OS_TYPE}" failed and exited with 100 during .

This seems to be due to Debian Wheezy end of life.
There are no longer wheezy related directories under https://deb.debian.org/debian/dists/

[bourtemb]

Unless somebody knows a way to make the Debian 7 Travis builds work again, I propose to disable/remove them.

[bourtemb]

Closed with #547

[bourtemb]

I found this announce on a Debian mailing list:
https://lists.debian.org/debian-devel-announce/2019/03/msg00006.html

Hello,

as Wheezy and Jessie have been integrated into the archive.debian.org
structure recently, we are now removing all of Wheezy and all non-LTS
architectures of Jessie from the mirror network starting today.
That is, only Jessie i386, amd64, armel and armhf will continue to be
hosted on the normal mirrors.

The data is, of course, not lost - the whole of it is synced
to archive.debian.org, so if you still need it you will be able to get
it from there.[1]

[1] Keep in mind that they have no security support at all!

The data is still available on archive.debian.org.
So, in theory, if debian:wheezy-backports docker base image is updated to point to archive.debian.org, it can still work...

We could also update the apt source configuration on our Debian 7 Docker file to point to archive.debian.org.
A bit like this example showing how to do for Debian squeeze:

https://gist.github.com/ricsiga/e8c35ba06715b86215a9da2613eafc28

[bourtemb]

There is already an issue created for the docker base image we are using:
debuerreotype/docker-debian-artifacts#65
So this will probably be fixed soon.

[bourtemb]

The Debian Docker base images we are using will be updated or renamed soon.
We will keep an eye on them.
In the mean time, #549 fixed the Debian 7 & Debian 8 Travis build issues.