Update vendor dependencies

Change-Id: I3b1ca9f2687388c831d9d46a4e1de413ffae06ac

vendor/github.com/google/cadvisor/container/mesos/client.go

@@ -70,6 +70,11 @@ func Client() (mesosAgentClient, error) {
 			),
 		}
 	})
+
+	_, err := mesosClient.getVersion()
+	if err != nil {
+		return nil, fmt.Errorf("failed to get version")
+	}
 	return mesosClient, nil
 }
 
@@ -134,6 +139,20 @@ func (self *client) getContainer(id string) (*mContainer, error) {
 	return nil, fmt.Errorf("can't locate container %s", id)
 }
 
+func (self *client) getVersion() (string, error) {
+	req := calls.NonStreaming(calls.GetVersion())
+	result, err := self.fetchAndDecode(req)
+	if err != nil {
+		return "", fmt.Errorf("failed to get mesos version: %v", err)
+	}
+	version := result.GetVersion
+
+	if version == nil {
+		return "", fmt.Errorf("failed to get mesos version")
+	}
+	return version.VersionInfo.Version, nil
+}
+
 func (self *client) getContainers() (mContainers, error) {
 	req := calls.NonStreaming(calls.GetContainers())
 	result, err := self.fetchAndDecode(req)
@@ -141,6 +160,10 @@ func (self *client) getContainers() (mContainers, error) {
 		return nil, fmt.Errorf("failed to get mesos containers: %v", err)
 	}
 	cntrs := result.GetContainers
+
+	if cntrs == nil {
+		return nil, fmt.Errorf("failed to get mesos containers")
+	}
 	return cntrs, nil
 }