[Python] Fix compilation failure on 32-bit platforms
[Python] Fix compilation failure on 32-bit platforms

Closes #91. 32-bit arch may needs some more specific attention at some point.

There is a separate issue, which is distutils on Apple's default Python 2.7 compiling C extensions in 32-bit mode. On my OSX 10.0 (64-bit) machine, a 2014 Macbook Pro Core i7, I see

```shell
$ arch
i386
```

Building feather with `/usr/bin/python setup.py build` invokes `gcc -arch i386` which is incorrect. I googled a bit but didn't find a conclusive explanation how to fix it, so if someone figures it out, let me know. Something something universal binaries.

Author: Wes McKinney <wesm@apache.org>

Closes #95 from wesm/bug/fix-apple-python-2.7 and squashes the following commits:

17dae74 [Wes McKinney] Prevent compilation failure with Apple Python erroniously compiling for i386 architecture

wesm/feather,wesm/feather,chris-b1/feather,chris-b1/feather,wesm/feather,wesm/feather,chris-b1/feather,wesm/feather,chris-b1/feather,wesm/feather,chris-b1/feather,wesm/feather,wesm/feather,chris-b1/feather