Fixes Issue #6 - wrong default value for site-amplification service d…
Created by: golden-usgs
…efault value
The default value for SITE_AMPLIFICATION_SERVICE_URL in questions.js is:
https://earthquake.usgs.gov/ws/designmaps/site_amplification.json
The default value should be:
https://earthquake.usgs.gov/ws/designmaps/site-amplification.json