Add e2e tests for Helm chart

Signed-off-by: Ricardo Lopes <ricardoapl.dev@gmail.com>

charts/ingress-nginx/ci/deployment-defaultbackend-values.yaml

@@ -0,0 +1,21 @@
+controller:
+  image:
+    repository: ingress-controller/controller
+    tag: 1.0.0-dev
+    digest: null
+  service:
+    type: ClusterIP
+
+defaultBackend:
+  enabled: true
+  extraEnvs:
+    - name: IS_METRICS_EXPORT
+      value: "false"
+    - name: METRICS_PORT
+      value: "8081"
+  service:
+    extraPorts:
+      - name: metrics
+        port: 8081
+        protocol: TCP
+        targetPort: 8081