`pip install` is broken on Linux and OSX

On Ubuntu:

``` bash
$ uname -a
Linux vm-home0.archive.org 3.5.0-32-generic #53~precise1-Ubuntu SMP Wed May 29 20:33:37 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

$ pip install warctools
Downloading/unpacking warctools
Could not find a version that satisfies the requirement warctools (from versions: 4.7.macosx-10.8-intel)
```

On OS X:

``` bash
$ uname -a
Darwin rajs-MacBook-Air-2.local 12.5.0 Darwin Kernel Version 12.5.0: Mon Jul 29 16:33:49 PDT 2013; root:xnu-2050.48.11~1/RELEASE_X86_64 x86_64

$ pip install warctools
Downloading/unpacking warctools
Downloading warctools-4.7.macosx-10.8-intel.tar.gz (54kB): 54kB downloaded
Running setup.py egg_info for package warctools
Traceback (most recent call last):
File "", line 16, in
IOError: [Errno 2] No such file or directory: '/private/tmp/testenv/build/warctools/setup.py'
Complete output from command python setup.py egg_info:
Traceback (most recent call last):

File "", line 16, in

IOError: [Errno 2] No such file or directory: '/private/tmp/testenv/build/warctools/setup.py'
```