added index
Merge branch 'master' of https://github.com/gem/oq-engine into add-index-to-hzrdi-hc
added migration
Merge pull request #1239 from matley/add-index-to-hzrdi-hc

Added index to hzrdi.hazard_site
Merge branch 'master' of https://github.com/gem/oq-engine into risk-base-calc-refactoring