Add CodeQL Scanning (#24)

This PR adds a CodeQL scanning workflow to the project

.github/workflows/codeql-analysis.yml

@@ -0,0 +1,32 @@
+name: "CodeQL"
+
+on:
+  push:
+    branches: [master, ]
+  pull_request:
+    branches: [master]
+  schedule:
+    - cron: '0 4 * * 3'
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+      with:
+        fetch-depth: 2
+
+    - run: git checkout HEAD^2
+      if: ${{ github.event_name == 'pull_request' }}
+
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v1
+
+    - name: Autobuild
+      uses: github/codeql-action/autobuild@v1
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v1