headless peripherals for TAP tests

.github/workflows/tap_test.yml

@@ -10,6 +10,10 @@ jobs:
     # The type of runner that the job will run on
     runs-on: ubuntu-latest
 
+    # Set environment variables for the whole job
+    env:
+      DISPLAY: :99
+
     strategy:
       fail-fast: false
       matrix:
@@ -26,6 +30,14 @@ jobs:
         with:
           path: "requirements.txt"
 
+      # These actions setup virtual peripherals in the headless environment
+      - name: Set up Headless Peripherals
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y xvfb
+          Xvfb :99 &
+          sudo apt-get install python3-tk python3-dev
+
       # Runs a set of commands using the runners shell
       - name: run Django/Turkle server
         run: |