Modified retrieval of version info to fix install issue.

If you try to install huxley within a clean environment, like virtualenv,
then setup tries to import huxley to get version information before the
dependencies are install.  This puts setup into a catch-22 as importing
huxley also tries to input uninstalled dependencies.
Merge pull request #18 from emanlove/master

Modified retrieval of version info to fix install issue.