use either urllib2 or urllib.request as necessary

saucebrush/utils.py

@@ -1,5 +1,10 @@
 import os
-import urllib2
+
+try:
+    from urllib.request import urlopen  # attemp py3 first
+except ImportError:
+    from urllib2 import urlopen         # fallback to py2
+
 """
     General utilities used within saucebrush that may be useful elsewhere.
 """
@@ -112,7 +117,7 @@ class RemoteFile(object):
         self._url = url
 
     def __iter__(self):
-        resp = urllib2.urlopen(self._url)
+        resp = urlopen(self._url)
         for line in resp:
             yield line.rstrip()
         resp.close()