Test with three different osc versions

Signed-off-by: Andrej Shadura <andrew.shadura@collabora.co.uk>

.gitlab-ci.yml

@@ -11,7 +11,7 @@ build:
   script:
   - apt install -y $PYTHON python3-pip devscripts
   - mk-build-deps -ir -t "apt-get -o Debug::pkgProblemResolver=yes --no-install-recommends -y"
-  - pip3 install .
+  - pip3 install --user --break-system-packages .
   - $PYTHON setup.py build sdist bdist
   - dpkg-buildpackage --no-sign
   - mkdir -p _build
@@ -30,8 +30,21 @@ test:
   - when: on_success
   needs:
   - build
+  parallel:
+    matrix:
+      - OSC_VERSION:
+        - default
+        - 1.4.0
+        - 1.6.2
   script:
-  - apt install -y ./_build/*deb dpkg-dev
+  - apt-get install -y osc dpkg-dev python3-pip
+  - |
+    if [ "$OSC_VERSION" != default ]
+    then
+      rm -rf /usr/lib/python3/dist-packages/osc*
+      pip install --user --break-system-packages "osc==$OSC_VERSION"
+    fi
+  - apt-get install -y ./_build/*deb
   - mkdir -p "$HOME"
   - |
     cat > ~/.oscrc <<EOF