dropbox: adapt code to recent library changes

dropbox/dropbox.go

@@ -290,7 +290,7 @@ func (f *FsDropbox) list(out fs.ObjectsChan) {
 			if !deltaPage.HasMore {
 				break
 			}
-			cursor = deltaPage.Cursor
+			cursor = deltaPage.Cursor.Cursor
 		}
 	}
 }

notes.txt

@@ -60,6 +60,7 @@ Bugs
   * When doing copy it recurses the whole of the destination FS which isn't necessary
 
 Making a release
+  * go get -u -f -v ./...
   * make test
   * make tag
   * edit README.md