Discontinue Java 7 and Debian Jessie version

End of life of Java 7 was April 2015. The only reason we use unsupported
Debian Jessie version is to support Java 7.

The way forward is:

1. Announce, that old Gerrit versions: 2.11 and 2.12 have eol for
community support
2. Announce, that 2.13 branch is now built with Java 8

Test Plan:

1. Build all dockers images
2. Start slave-bazel docker image:

docker run --privileged -it gerritforge/gerrit-ci-slave-bazel:debian-stretch bash

3. su - jenkins
4. clone gerrit:

git clone --recurse-submodules https://gerrit.googlesource.com/gerrit

5. cd gerrit
6. Build with bazel:

bazel build :release

7. Switch to stable-2.13 branch:

git checkout stable-2.13

8. Build with buck:

buck build :release

Change-Id: I427f5291a2f5683a447e806f7681c291ded7aa62
21 files changed
tree: 1ed989976872e73f0dbe940a3466d1a942c0e939
  1. .gitignore
  2. jenkins-docker/
  3. jenkins/
  4. worker/