• Added Reference Document: NEHRP-2009
• Added Reference Document: NEHRP-2015
• Added Reference Document: IBC-2012
• Added Reference Document: IBC-2015
• Addressed some technical debt issues

https://github.com/usgs/earthquake-design-ws/compare/v0.5.0...v0.6.0

Deployed to production: 2017-10-06