adding retryon support

Signed-off-by: brandoncate <brandon.cate@shipt.com>

test/contour/test-custom.sh

@@ -0,0 +1,57 @@
+#!/usr/bin/env bash
+
+cat <<EOF | kubectl apply -f -
+apiVersion: flagger.app/v1beta1
+kind: Canary
+metadata:
+  name: podinfo
+  namespace: test
+spec:
+  provider: contour
+  targetRef:
+    apiVersion: apps/v1
+    kind: Deployment
+    name: podinfo
+  progressDeadlineSeconds: 60
+  service:
+    port: 80
+    targetPort: 9898
+    retries:
+      attempts: 3
+      perTryTimeout: 5s
+      retryOn: connect-failure,5xx
+  analysis:
+    interval: 15s
+    threshold: 15
+    maxWeight: 50
+    stepWeight: 10
+    metrics:
+    - name: request-success-rate
+      threshold: 99
+      interval: 1m
+    - name: request-duration
+      threshold: 500
+      interval: 1m
+    webhooks:
+      - name: acceptance-test
+        type: pre-rollout
+        url: http://flagger-loadtester.test/
+        timeout: 10s
+        metadata:
+          type: bash
+          cmd: "curl -sd 'test' http://podinfo-canary/token | grep token"
+      - name: contour-acceptance-test
+        type: pre-rollout
+        url: http://flagger-loadtester.test/
+        timeout: 10s
+        metadata:
+          type: bash
+          cmd: "curl -sd 'test' -H 'Host: app.example.com' http://envoy.projectcontour/token | grep token"
+      - name: load-test
+        url: http://flagger-loadtester.test/
+        timeout: 5s
+        metadata:
+          type: cmd
+          cmd: "hey -z 1m -q 5 -c 2 -host app.example.com http://envoy.projectcontour"
+          logCmdOutput: "true"
+EOF