Initialize class properly
Initialize in struct
Make pylint happy
Revert "Initialize in struct"

This reverts commit 168b6996fa53729a0a39e8985b67956b4c3a365a.

Apparently some compilers can't handle initialization to a function
defined in another module.
Clean up metadata object creation
Don't test extension on PyPy
Merge pull request #8 from maxmind/greg/extension-cleanup

Clean up object initialization