ci: Force pytest colors for CI

For some reason, pytest on GitHub doesn't display any colors.

.github/workflows/ci.yml

@@ -50,6 +50,7 @@ jobs:
         QUTE_BDD_WEBENGINE: "${{ matrix.image != 'archlinux-webkit' }}"
         DOCKER: "${{ matrix.image }}"
         CI: true
+        PYTEST_ADDOPTS: "--color=yes"
       options: --privileged --tty
     steps:
       - uses: actions/checkout@v2

tox.ini

@@ -14,7 +14,7 @@ setenv =
     pyqt{,57,59,510,511,512,513,514,515}: LINK_PYQT_SKIP=true
     pyqt{,57,59,510,511,512,513,514,515}: QUTE_BDD_WEBENGINE=true
     cov: PYTEST_ADDOPTS=--cov --cov-report xml --cov-report=html --cov-report=
-passenv = PYTHON DISPLAY XAUTHORITY HOME USERNAME USER CI XDG_* QUTE_* DOCKER QT_QUICK_BACKEND
+passenv = PYTHON DISPLAY XAUTHORITY HOME USERNAME USER CI XDG_* QUTE_* DOCKER QT_QUICK_BACKEND PYTEST_ADDOPTS
 basepython =
     py35: {env:PYTHON:python3.5}
     py36: {env:PYTHON:python3.6}