Issue #15: Cython needs to be in setup_requires

We need Cython BEFORE installing kmod (done with setup_requires),
and AFTER installation - during runtime (done with install_requires)
(cherry picked from commit ff812e2075949464359585dadad3868f74d462e7)

Signed-off-by: Guy Rozendorn <guy@rzn.co.il>
TRIVIAL creating infi.kmod-0.9.0.3 until issue #15 is resolved