Improved setup file for installing numpy and cython

[lzala]

• This change helps when installing the module as part of the requirements of another module and numpy, cython are missing.

Signed-off-by: Lucian Zala zala.lucian@gmail.com

[lzala]

Hi Matt,

The change I am proposing is trying to improve the setup installation for numpy and cython.

The 'issue' I currently have is: When I am trying to install bandmat with pip install -r requirements.txt as part of requirements.txt of another project I get an error because numpy/cython were not installed.

Of course the solution is to install it by hand, but I was thinking that doing this with setup_requires may be better. Please have a look over the PR and let me know about your thoughts.

Thanks, Lucian