Update README.md

Author: kvaps

README.md

@@ -69,7 +69,7 @@ $ sudo ./bin/imageplugin --endpoint tcp://127.0.0.1:10000 --nodeid CSINode -v=5
 Get ```csc``` tool from https://github.com/rexray/gocsi/tree/master/csc
 
 ### Mount the image
-$ csc -e tcp://127.0.0.1:10000 node publish abcdefg --attrib image=kfox1111/misc:test --cap MULTI_NODE_MULTI_WRITER,block --target-path /tmp/csi
+$ csc -e tcp://127.0.0.1:10000 node publish abcdefg --vol-context image=kfox1111/misc:test --cap MULTI_NODE_MULTI_WRITER,block --target-path /tmp/csi
 
 ### Unmount the image
 $ csc -e tcp://127.0.0.1:10000 node unpublish abcdefg --target-path /tmp/csi