switch requirements order to force greenlet to install before gevent

requirements.txt

@@ -7,9 +7,9 @@ netifaces>=0.10,<0.11  # https://bitbucket.org/al45tair/netifaces/src/
 pycryptodomex>=3.6,<3.7  # https://github.com/Legrandin/pycryptodome/blob/master/Changelog.rst
 psutil>=5.5,<5.6  # https://github.com/giampaolo/psutil/blob/master/HISTORY.rst
 requests>=2.22,<2.23  # https://pypi.python.org/pypi/requests
-gevent==20.12.0  # http://www.gevent.org/changelog.html
 # Limit greenlet version for binary compatibility with gevent 20.12 wheels
 greenlet==1.0.0
+gevent==20.12.0  # http://www.gevent.org/changelog.html
 werkzeug>=0.16,<0.17  # https://github.com/pallets/werkzeug/blob/master/CHANGES
 patool>=1.12,<1.13  # https://github.com/wummel/patool/blob/master/doc/changelog.txt
 bcrypt>=3.1,<3.2  # https://github.com/pyca/bcrypt/