Fixed compatibility issue with pyzmq 13.0.0

docs/installation.rst

@@ -23,13 +23,13 @@ Installing ZeroMQ
 -----------------
 
 If you intend to run Locust distributed across multiple processes/machines, we recommend you to also 
-install **pyzmq** and gevent-zeromq::
+install **pyzmq**::
 
-    pip install pyzmq gevent-zeromq
+    pip install pyzmq
 
 or::
 
-    easy_install pyzmq gevent-zeromq
+    easy_install pyzmq
 
 Installing Locust on Windows
 ----------------------------

examples/vagrant/vagrant.sh

@@ -9,7 +9,7 @@ apt-get -y update
 apt-get -y install build-essential python-pip python-dev libevent-dev libzmq-dev
 cd /vagrant
 
-pip install -r requirements.txt --use-mirrors pyzmq gevent-zeromq supervisor
+pip install -r requirements.txt --use-mirrors pyzmq supervisor
 
 # Checkout and install latest Locust from Github
 python setup.py develop

locust/rpc/__init__.py

@@ -3,7 +3,7 @@
 try:
     import zmqrpc as rpc
 except ImportError:
-    warnings.warn("WARNING: Using pure Python socket RPC implementation instead of zmq. This will not affect you if you're not running locust in distributed mode, but if you are, we recommend you to install the python packages: pyzmq and gevent-zeromq")
+    warnings.warn("WARNING: Using pure Python socket RPC implementation instead of zmq. If running in distributed mode, this could cause a performance decrease. We recommend you to install the pyzmq python package when running in distributed mode.")
     import socketrpc as rpc
 
 from .protocol import Message

locust/rpc/zmqrpc.py

@@ -1,4 +1,4 @@
-from gevent_zeromq import zmq
+import zmq.green as zmq
 
 from .protocol import Message