Update image version to v1.0.0-canary

This PR updates the image version to v1.0.0-canary so that the official v1.0.0 image can be reserved.

Author: xing-yang

Makefile

@@ -16,7 +16,7 @@
 
 REGISTRY_NAME=quay.io/k8scsi
 IMAGE_NAME=csi-snapshotter
-IMAGE_VERSION=v1.0.0
+IMAGE_VERSION=v1.0.0-canary
 IMAGE_TAG=$(REGISTRY_NAME)/$(IMAGE_NAME):$(IMAGE_VERSION)
 
 REV=$(shell git describe --long --tags --match='v*' --dirty)