updated dependencies

vendor/golang.org/x/net/webdav/file.go

@@ -163,6 +163,7 @@ type memFS struct {
 //   - "/", "foo", false
 //   - "/foo/", "bar", false
 //   - "/foo/bar/", "x", true
+//
 // The frag argument will be empty only if dir is the root node and the walk
 // ends at that root node.
 func (fs *memFS) walk(op, fullname string, f func(dir *memFSNode, frag string, final bool) error) error {
@@ -546,11 +547,11 @@ func (f *memFile) Seek(offset int64, whence int) (int64, error) {
 	npos := f.pos
 	// TODO: How to handle offsets greater than the size of system int?
 	switch whence {
-	case os.SEEK_SET:
+	case io.SeekStart:
 		npos = int(offset)
-	case os.SEEK_CUR:
+	case io.SeekCurrent:
 		npos += int(offset)
-	case os.SEEK_END:
+	case io.SeekEnd:
 		npos = len(f.n.data) + int(offset)
 	default:
 		npos = -1