Add Github Action to run tests

.github/workflows/run-tests.yml

@@ -0,0 +1,33 @@
+name: Build and run tests
+
+on:
+  push:
+    branches: [ master, develop ]
+  pull_request:
+    branches: [ master, develop ]
+  workflow_dispatch:
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Set up Python
+      uses: actions/setup-python@v2
+      with:
+        python-version: '3.8'
+    - name: Clone ns-3
+      run: git clone https://gitlab.com/nsnam/ns-3-dev
+    - uses: actions/checkout@v2
+      with:
+        path: 'ns-3-dev/src/lorawan'
+    - name: Compile and run tests
+      run: |
+        cd ns-3-dev/
+        cp utils/.ns3rc ./
+        sed -i "s/all_modules/lorawan/" .ns3rc
+        sed -i "s/False/True/" .ns3rc
+        ./ns3 configure
+        ./ns3 build
+        ./test.py -n -s lorawan