Updated py-requests to 2.5.1

Changed ftp.NetBSD.org to pypi.python.org

Behavioural Changes

    Only catch HTTPErrors in raise_for_status (#2382)

Bugfixes

    Handle LocationParseError from urllib3 (#2344)
    Handle file-like object filenames that are not strings (#2379)
    Unbreak HTTPDigestAuth handler. Allow new nonces to be negotiated (#2389)

(imil)