Add __version__ to __init__.py

pygeoip/__init__.py

@@ -20,6 +20,7 @@ GNU General Public License for more details.
 You should have received a copy of the GNU Lesser General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/lgpl.txt>.
 """
+__version__ = "0.3.1"
 
 import os
 import socket