github/workflows: Add workflow to build and test unix dev variant.

Signed-off-by: Damien George <damien@micropython.org>

.github/workflows/ports_unix.yml

@@ -51,6 +51,18 @@ jobs:
       if: failure()
       run: tests/run-tests.py --print-failures
 
+  dev:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Build
+      run: source tools/ci.sh && ci_unix_dev_build
+    - name: Run main test suite
+      run: source tools/ci.sh && ci_unix_dev_run_tests
+    - name: Print failures
+      if: failure()
+      run: tests/run-tests.py --print-failures
+
   coverage:
     runs-on: ubuntu-latest
     steps: