fm_duplicate: create folder paths up to destination

duplicating foo/bar/file to foo/baz/file didn't work if the folder baz
didn't exists.

fixes #80

Author: math2001

commands/duplicate.py

@@ -46,6 +46,12 @@ def duplicate(self, dst, input_path):
             sublime.error_message("Destination is the same with the source.")
             return
 
+        # remove right trailing slashes, because os.path.dirname('foo/bar/')
+        # returns foo/bar rather foo/
+        dst = dst.rstrip("/")
+
+        os.makedirs(os.path.dirname(dst), exist_ok=True)
+
         if os.path.isdir(self.origin):
             if not os.path.exists(dst):
                 shutil.copytree(self.origin, dst)