use the pinned image.

Dispatchfile

@@ -10,9 +10,13 @@ gitResource("kba-git-resource", url = "$(context.git.url)", revision = "$(contex
 dindTask("dispatch-integration-test",
          inputs = ["kba-git-resource"],
          steps = [
+             v1.Container(
+                 name="fetch-master",
+                 workingDir="/workspace/kba-git-resource",
+                 args=["git", "fetch", "origin", "master"]),
              v1.Container(
                  name = "dispatch-integration-test",
-		 image = "mesosphere/kubeaddons-ci:dispatch@sha256:80a6f3c8775133b4ad2fab3d44ab4fbb4b541dbc03fcdb296b13f67611427d8c",
+                 image = "mesosphere/kubeaddons-ci:dispatch@sha256:80a6f3c8775133b4ad2fab3d44ab4fbb4b541dbc03fcdb296b13f67611427d8c",
                  command = ["/entrypoint.sh","make","dispatch-test"],
                  workingDir = "/workspace/kba-git-resource",
                  env = [k8s.corev1.EnvVar(name = "DISPATCH_CI", value = "true"),