Updates the requirements on gevent to permit the latest version.

Sourced from gevent's changelog.

=========================== Changes before gevent 1.0

.. currentmodule:: gevent

Release 0.13.8 (September 6, 2012)

• Fixed :issue:80: gevent.httplib failed with RequestFailed errors because timeout was reset to 1s. Patch by Tomasz Prus.
• core: fix compilation with the latest Cython: remove emit_ifdef/emit_else/emit_endif.
• Fixed :issue:132: gevent.socket.gethostbyname() now does ascii encoding and uses gevent's resolver rather than calling built-in resolver. Patch by Alexey Borzenkov.

Release 0.13.7 (April 12, 2012)

• Fixed :issue:94: fallback to buffer if memoryview fails in _get_memory on python 2.7.
• Fixed :issue:103: Queue(None).full() returns False now (previously it returned True).
• Fixed :issue:112: threading._sleep is not patched. Thanks to David LaBissoniere.
• Fixed :issue:115: _dummy gets unexpected Timeout arg.

Release 0.13.6 (May 2, 2011)

• Added __copy__ method to :class:gevent.local.local class that implements copy semantics compatible with built-in threading.local. Patch by Galfy Pundee.
• Fixed :class:StreamServer class to catch EWOULDBLOCK rather than EAGAIN. This fixes lots of spurious tracebacks on Windows where these two constants are not the same. Patch by Alexey Borzenkov.
• Fixed :issue:65: :func:fork now calls event_reinit only in the child process; otherwise the process could hang when using libevent2. Patch by Alexander Boudkar.

Release 0.13.5 (Apr 21, 2011)

• Fixed build problem on Python 2.5

Release 0.13.4 (Apr 11, 2011)

• Fixed :exc:TypeError that occurred when environ["wsgi.input"].read function was called with an integer argument.
• Fixed :issue:63: :func:monkey.patch_thread now patches :mod:threading too, even if it's already imported. Patch by Shaun Lindsay.
• Fixed :issue:64: :func:joinall and :func:killall functions used to hang if their argument contained duplicate greenlets.
• Fixed :issue:69: :class:pywsgi.WSGIServer reported "Connection reset by peer" if the client did not close the connection gracefully after the last request. Such errors are now ignored.
• Fixed :issue:67: Made :class:wsgi.WSGIServer add REQUEST_URI to environ. Patch by Andreas Blixt.
• Fixed :issue:71: monkey patching httplib with :mod:gevent.httplib used to break HTTPSConnection. Patch by Nick Barkas.
• Fixed :issue:74: :func:create_connection <gevent.socket.create_connection> now raises proper exception when getaddrinfo fails.
• Fixed :meth:BaseServer.__repr__ method, :attr:BaseServer.server_host and :attr:BaseServer.server_port attributes to handle the case of AF_UNIX addresses properly. Previously they assumed address is always a tuple.
• Fixed :class:pywsgi.WSGIServer to handle AF_UNIX listeners. The server now sets environ["SERVER_NAME"] and environ["SERVER_PORT"] to empty string in such case.

... (truncated)

• 4f68410 Preparing release 26.8.0
• 10489c5 Merge pull request #2199 from florentinl/florentin.labelle/fix/hubless-thread...
• d4f5f09 Document the args[0] cross-thread wakeup mechanism
• 9b04991 Run test_cross_thread_callback_can_run_before_scheduling_returns on all backends
• ce7996d Address review comments: document cross-thread race, drop unneeded cpdef
• 5288a6e Add missing @​ignores_leakcheck to new cross-thread test
• c72eda0 Fix cross-thread notifier scheduling race
• 908b937 Merge pull request #2195 from ddorian/fix-popen-exit-reentrant-close
• b58795f Merge pull request #2191 from ddorian/fix-1865-global-shutdown-lock
• ede2e71 Always use 'versionchanged:: NEXT' to let the release machinery fill in the c...
• Additional commits viewable in compare view