Update GitHub workflows

Separated the deploy and test workflow so that pull requests dont generate a new docker image

.github/workflows/deploy.yml

@@ -1,10 +1,8 @@
-name: Build docker container
+name: Publish docker container
 
 on:
   push:
     branches: [master]
-  pull_request:
-    branches: [master]
 
 jobs:
   test:

.github/workflows/test.yml

@@ -0,0 +1,23 @@
+name: Run python tests
+
+on:
+  pull_request:
+    branches: [master]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: "3.8"
+
+      - name: Install dependencies
+        run: pip install -r requirements.txt
+
+      - name: Run tests
+        run: python -m unittest