[pygobject] CI: pin coverage.py version to 4.x, we don't support 5.x yet

[Christoph Reiter <creiter src gnome org>]

commit 5a3033d8e249ad4a739a65bc49cc1c2a4cb142b9
Author: Christoph Reiter <reiter christoph gmail com>
Date:   Tue Dec 17 17:40:23 2019 +0100

    CI: pin coverage.py version to 4.x, we don't support 5.x yet
    
    The saved format has changed and we currently depend on it for
    merging Windows and Unix paths.

 .gitlab-ci/coverage-docker.sh   | 2 +-
 .gitlab-ci/test-docker-old.sh   | 2 +-
 .gitlab-ci/test-docker.sh       | 2 +-
 .gitlab-ci/test-flatpak-gtk4.sh | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/.gitlab-ci/coverage-docker.sh b/.gitlab-ci/coverage-docker.sh
index 2a51d036..78653efe 100755
--- a/.gitlab-ci/coverage-docker.sh
+++ b/.gitlab-ci/coverage-docker.sh
@@ -2,7 +2,7 @@
 
 set -e
 
-python -m pip install coverage
+python -m pip install "coverage<5"
 
 # Make the Windows paths match our current layout
 python ./.gitlab-ci/fixup-cov-paths.py coverage/.coverage* coverage/*.lcov
diff --git a/.gitlab-ci/test-docker-old.sh b/.gitlab-ci/test-docker-old.sh
index 8d451bc0..0154c7aa 100755
--- a/.gitlab-ci/test-docker-old.sh
+++ b/.gitlab-ci/test-docker-old.sh
@@ -16,6 +16,6 @@ mkdir -p "${CCACHE_DIR}"
 
 # test
 python -m pip install git+https://github.com/pygobject/pycairo.git
-python -m pip install pytest pytest-faulthandler coverage
+python -m pip install pytest pytest-faulthandler "coverage<5"
 python setup.py build_tests
 xvfb-run -a python -m coverage run tests/runtests.py
diff --git a/.gitlab-ci/test-docker.sh b/.gitlab-ci/test-docker.sh
index 7205f8b6..d3217be6 100755
--- a/.gitlab-ci/test-docker.sh
+++ b/.gitlab-ci/test-docker.sh
@@ -22,7 +22,7 @@ mkdir -p "${CCACHE_DIR}"
 mkdir -p "${COV_DIR}"
 
 python -m pip install git+https://github.com/pygobject/pycairo.git
-python -m pip install flake8 pytest pytest-faulthandler coverage
+python -m pip install flake8 pytest pytest-faulthandler "coverage<5"
 
 export CFLAGS="-coverage -ftest-coverage -fprofile-arcs -Werror"
 
diff --git a/.gitlab-ci/test-flatpak-gtk4.sh b/.gitlab-ci/test-flatpak-gtk4.sh
index 189d63cd..acfc3be0 100755
--- a/.gitlab-ci/test-flatpak-gtk4.sh
+++ b/.gitlab-ci/test-flatpak-gtk4.sh
@@ -7,7 +7,7 @@ export COVERAGE_FILE="${COV_DIR}/.coverage.gtk4"
 mkdir -p "${COV_DIR}"
 
 export TEST_GTK_VERSION=4.0
-python3 -m pip install --user pytest pytest-faulthandler coverage
+python3 -m pip install --user pytest pytest-faulthandler "coverage<5"
 python3 setup.py build_tests
 python3 -m coverage run tests/runtests.py
 chmod -R 777 "${COV_DIR}"
\ No newline at end of file