Update dependency on certifi

Originally reported by: **jaraco (Bitbucket: [jaraco](http://bitbucket.org/jaraco), GitHub: [jaraco](http://github.com/jaraco))**

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Setuptools[ssl] currently depends on certify 0.0.8, an old version. It should probably be bumped.

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- Bitbucket: https://bitbucket.org/pypa/setuptools/issue/162
