Merge pull request benoitc#331 from bobby-beckmann/master

Epic change to support gevent 1.0b2

gunicorn/workers/ggevent.py

@@ -20,6 +20,7 @@
 from gevent.pool import Pool
 from gevent.server import StreamServer
 from gevent import pywsgi
+from gevent import core
 
 import gunicorn
 from gunicorn.workers.async import AsyncWorker