Add trivy vulnerability scanner github action

.github/workflows/trivy.yaml

@@ -0,0 +1,54 @@
+name: Trivy vulnerability scanner
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-18.04
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Install go
+        uses: actions/setup-go@v2
+        with:
+          go-version: ^1.17
+
+      - name: Build images from Dockerfile
+        run: |
+          make
+          docker build -t test/velero-plugin-for-vsphere:latest -f Dockerfile-plugin --output=type=docker --label revision=latest .
+          docker build -t test/data-manager-for-plugin:latest -f Dockerfile-datamgr --output=type=docker --label revision=latest .
+          docker build -t test/backup-driver:latest -f Dockerfile-backup-driver --output=type=docker --label revision=latest .
+      - name: Run Trivy vulnerability scanner on velero-plugin-for-vsphere image
+        uses: aquasecurity/trivy-action@master
+        with:
+          image-ref: 'test/velero-plugin-for-vsphere:latest'
+          format: 'table'
+          exit-code: '1'
+          ignore-unfixed: true
+          vuln-type: 'os,library'
+          severity: 'CRITICAL,HIGH,MEDIUM,LOW,UNKNOWN'
+
+      - name: Run Trivy vulnerability scanner on data-manager-for-plugin image
+        uses: aquasecurity/trivy-action@master
+        with:
+          image-ref: 'test/data-manager-for-plugin:latest'
+          format: 'table'
+          exit-code: '1'
+          ignore-unfixed: true
+          vuln-type: 'os,library'
+          severity: 'CRITICAL,HIGH,MEDIUM,LOW,UNKNOWN'
+
+      - name: Run Trivy vulnerability scanner on backup-driver image
+        uses: aquasecurity/trivy-action@master
+        with:
+          image-ref: 'test/backup-driver:latest'
+          format: 'table'
+          exit-code: '1'
+          ignore-unfixed: true
+          vuln-type: 'os,library'
+          severity: 'CRITICAL,HIGH,MEDIUM,LOW,UNKNOWN'