.gitlab-ci.yml: run our runtime tests

This commit improves our .gitlab-ci.yml logic to execute our runtime
tests located in support/testing/. To do so, this commit:

 - Adds more Debian packages to be installed, namely the nose2 and
   pexpect packages needed by the runtime testing infrastructure, as
   well as the necessary Qemu emulators

 - The description of how to run the runtime tests. Each test is
   executed as a separate Gitlab CI job, so that the status of each
   test is easily visible in the Gitlab CI web interface.

 - The Makefile is improved to auto-generate .gitlab-ci.yml from
   .gitlab-ci.yml.in, like we're doing for defconfigs. Since the
   dependencies of .gitlab-ci.yml are no longer correct, we abandon
   them and instead make it a PHONY target.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
[Arnout: simplify .gitlab-ci.in a little, removing redundant stuff;
         make .gitlab-ci.yml a PHONY target]
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

.gitlab-ci.yml.in

@@ -13,6 +13,7 @@ before_script:
     - apt-get install -y -qq --no-install-recommends
         build-essential locales bc ca-certificates file rsync gcc-multilib
         git bzr cvs mercurial subversion libc6:i386 unzip wget cpio
+        python-nose2 python-pexpect qemu-system-arm qemu-system-x86
     # To be able to generate a toolchain with locales, enable one UTF-8 locale
     - sed -i 's/# \(en_US.UTF-8\)/\1/' /etc/locale.gen
     - /usr/sbin/locale-gen
@@ -57,3 +58,10 @@ check-DEVELOPERS:
             - output/build/build-time.log
             - output/build/packages-file-list.txt
 
+.runtime_test: &runtime_test
+    script: ./support/testing/run-tests -o test-output/ -d test-dl/ ${CI_BUILD_NAME}
+    artifacts:
+        when: always
+        expire_in: 2 weeks
+        paths:
+            - test-output/*.log