help pip to not install conflicting requirements

.github/workflows/unittest.yml

@@ -26,6 +26,8 @@ jobs:
         python-version: ${{ matrix.python-version }}
     - name: Install system dependencies
       run: sudo make deps-ubuntu
+#    - name: Install system dependencies (screenshot)
+#      run: sudo apt install xrandr imagemagick
     - name: Install dependencies and browse-ocrd
       run: make deps-dev deps install
     - name: Lint with flake8
@@ -42,9 +44,9 @@ jobs:
       with:
         name: Unit Test Results (Python ${{ matrix.python-version }})
         path: unittest.xml
-    - name: Run browse-ocrd
-      run: browse-ocrd tests/example/workspaces/kant_aufklaerung_1784_missing_xml/mets.xml
-    - name: Screenshot
-      uses: OrbitalOwen/[email protected]
-      with:
-        file-name: 'desktop.jpg'
+#    - name: Run browse-ocrd
+#      run: browse-ocrd tests/example/workspaces/kant_aufklaerung_1784_missing_xml/mets.xml
+#    - name: Screenshot
+#      uses: OrbitalOwen/[email protected]
+#      with:
+#        file-name: 'desktop.jpg'

requirements-dev.txt

@@ -1,5 +1,6 @@
 wheel
 setuptools
 unittest-xml-reporting
+html-testRunner
 flake8
 mypy

requirements.txt

@@ -1,6 +1,6 @@
 ocrd
 Pillow
-numpy
+numpy<1.19.0,>=1.17.0
 opencv-python-headless
 PyGObject
 python-magic