bump certifi to 2016.2.28

Signed-off-by: Gabi Davar <grizzly.nyo@gmail.com>

setup.py

@@ -146,10 +146,10 @@ setup_params = dict(
         """).strip().splitlines(),
     extras_require={
         "ssl:sys_platform=='win32'": "wincertstore==0.2",
-        "certs": "certifi==2015.11.20",
+        "certs": "certifi==2016.2.28",
     },
     dependency_links=[
-        'https://pypi.python.org/packages/source/c/certifi/certifi-2015.11.20.tar.gz#md5=25134646672c695c1ff1593c2dd75d08',
+        'https://pypi.python.org/packages/source/c/certifi/certifi-2016.2.28.tar.gz#md5=5d672aa766e1f773c75cfeccd02d3650',
         'https://pypi.python.org/packages/source/w/wincertstore/wincertstore-0.2.zip#md5=ae728f2f007185648d0c7a8679b361e2',
     ],
     scripts=[],