Update to CSI spec 1.4

Author: xing-yang

go.mod

@@ -3,7 +3,7 @@ module github.com/kubernetes-csi/external-snapshotter/v4
 go 1.16
 
 require (
-	github.com/container-storage-interface/spec v1.3.0
+	github.com/container-storage-interface/spec v1.4.0
 	github.com/fsnotify/fsnotify v1.4.9
 	github.com/go-logr/logr v0.3.0 // indirect
 	github.com/golang/mock v1.4.4

go.sum

@@ -124,8 +124,9 @@ github.com/cockroachdb/datadriven v0.0.0-20190809214429-80d97fb3cbaa/go.mod h1:z
 github.com/codahale/hdrhistogram v0.0.0-20161010025455-3a0bb77429bd/go.mod h1:sE/e/2PUdi/liOCUjSTXgM1o87ZssimdTWN964YiIeI=
 github.com/codegangsta/negroni v1.0.0/go.mod h1:v0y3T5G7Y1UlFfyxFn/QLRU4a2EuNau2iZY63YTKWo0=
 github.com/container-storage-interface/spec v1.2.0/go.mod h1:6URME8mwIBbpVyZV93Ce5St17xBiQJQY67NDsuohiy4=
-github.com/container-storage-interface/spec v1.3.0 h1:wMH4UIoWnK/TXYw8mbcIHgZmB6kHOeIsYsiaTJwa6bc=
 github.com/container-storage-interface/spec v1.3.0/go.mod h1:6URME8mwIBbpVyZV93Ce5St17xBiQJQY67NDsuohiy4=
+github.com/container-storage-interface/spec v1.4.0 h1:ozAshSKxpJnYUfmkpZCTYyF/4MYeYlhdXbAvPvfGmkg=
+github.com/container-storage-interface/spec v1.4.0/go.mod h1:6URME8mwIBbpVyZV93Ce5St17xBiQJQY67NDsuohiy4=
 github.com/containerd/cgroups v0.0.0-20200531161412-0dbf7f05ba59/go.mod h1:pA0z1pT8KYB3TCXK/ocprsh7MAkoW8bZVzPdih9snmM=
 github.com/containerd/console v0.0.0-20180822173158-c12b1e7919c1/go.mod h1:Tj/on1eG8kiEhd0+fhSDzsPAFESxzBBvdyEgyryXffw=
 github.com/containerd/console v1.0.0/go.mod h1:8Pf4gM6VEbTNRIT26AyyU7hxdQU3MvAvxVI0sc00XBE=