Up requests version to 2.1.0, now that it's released

requirements.txt

@@ -13,8 +13,7 @@ wsgiref==0.1.2
 blinker==1.3
 gevent==0.13.8
 jsonschema==2.0.0
-requests==2.0.1
--e git+https://github.com/kennethreitz/requests.git@947375e982482de23bf74eac7d84140126862ac5
+requests==2.1.0
 # ndg & pyasn required for SNI
 ndg-httpsclient==0.3.2
 pyasn1==0.1.7