Tweak test__refcount.py timeout on CI.

dev-requirements.txt

 setuptools
 wheel
-cython>=0.25
+cython>=0.25.1
 greenlet>=0.4.10
 prospector[with_pyroma]
 coverage>=4.0

doc/whatsnew_1_2.rst

@@ -15,7 +15,7 @@ Platform Support
 
 gevent 1.2 supports Python 2.7, 3.4, 3.5 and 3.6 on the CPython
 (`python.org`_) interpreter. It also supports `PyPy2`_ 4.0.1 and above
-(PyPy2 5.2 or higher is recommended) and PyPy3 5.5.0.
+(PyPy2 5.4 or higher is recommended) and PyPy3 5.5.0.
 
 
 .. caution:: Support for Python 2.6 was removed. Support for Python 3.3 is only

src/greentest/test__refcount.py

@@ -56,7 +56,8 @@ import socket
 socket._realsocket = Socket
 
 SOCKET_TIMEOUT = 0.1
-
+if greentest.RUNNING_ON_CI:
+    SOCKET_TIMEOUT *= 2
 
 def init_server():
     s = socket.socket()