Update version to 0.13.0
Update version to 0.13.0

Recent celery changes included two big changes:

* Use of celery binary instead of paster to launch workers
* Solr config file is now called schema.xml (not openspending_schema.xml)

This calls for a new version (but not version 1.0.0).

johnjohndoe/spendb,USStateDept/FPA_Core,spendb/spendb,johnjohndoe/spendb,nathanhilbert/FPA_Core,johnjohndoe/spendb,openspending/spendb,CivicVision/datahub,USStateDept/FPA_Core,openspending/spendb,openspending/spendb,nathanhilbert/FPA_Core,pudo/spendb,pudo/spendb,spendb/spendb,CivicVision/datahub,spendb/spendb,pudo/spendb,USStateDept/FPA_Core,nathanhilbert/FPA_Core,CivicVision/datahub