Run test suites separately

This way, if e.g. the unit tests pass but the acceptance tests fail (as
happened in PR #11), that information will be evident before
investigating the specific problem.

.github/workflows/run-tests.yml → .github/workflows/acceptance-tests.yml

@@ -1,4 +1,4 @@
-name: Run Tests
+name: Acceptance Tests
 
 on:
   push:
@@ -10,7 +10,5 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
-    - name: Run unit tests
-      run: 'make test'
     - name: Run acceptance tests
       run: 'make features'

.github/workflows/unit-tests.yml

@@ -0,0 +1,14 @@
+name: Unit Tests
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Run unit tests
+      run: 'make test'