Merge pull request matplotlib#2406 from cpelley/fixed_stats-retrieve

BUG: Fixed github stats retrieval

Author: pelson

tools/github_stats.py

@@ -13,7 +13,7 @@
 
 from datetime import datetime, timedelta
 from subprocess import check_output
-from urllib import urlopen
+from urllib2 import urlopen
 
 #-----------------------------------------------------------------------------
 # Globals