Python 3 compatibility fix

digimarks.py

@@ -6,6 +6,11 @@ import hashlib
 import os
 import shutil
 import sys
+try:
+    # Python 3
+    from urllib.parse import urljoin, urlparse, urlunparse
+except ImportError:
+    # Python 2
     from urlparse import urljoin, urlparse, urlunparse
 
 import bs4