Bundle CodeQL, FOSSA, Snyk as jobs in workflow

Signed-off-by: Hidde Beydals <hello@hidde.co>

.github/workflows/scan.yaml

@@ -0,0 +1,55 @@
+name: Scan
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+  schedule:
+    - cron: '18 10 * * 3'
+
+jobs:
+  fossa:
+    name: FOSSA
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Run FOSSA scan and upload build data
+        uses: fossa-contrib/fossa-action@v1
+        with:
+          # FOSSA Push-Only API Token
+          fossa-api-key: 5ee8bf422db1471e0bcf2bcb289185de
+          github-token: ${{ github.token }}
+
+  snyk:
+    name: Snyk
+    runs-on: ubuntu-latest
+    if: ${{ github.repository_owner == 'fluxcd' }}
+    steps:
+      - uses: actions/checkout@v2
+      - name: Run Snyk to check for vulnerabilities
+        uses: snyk/actions/golang@master
+        continue-on-error: true
+        env:
+          SNYK_TOKEN: ${{ secrets.SNYK_TOKEN }}
+        with:
+          args: --sarif-file-output=snyk.sarif
+      - name: Upload result to GitHub Code Scanning
+        uses: github/codeql-action/upload-sarif@v1
+        with:
+          sarif_file: snyk.sarif
+
+  codeql:
+    name: CodeQL
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@v1
+        with:
+          languages: go
+      - name: Autobuild
+        uses: github/codeql-action/autobuild@v1
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@v1