Merge branch 'info-update' into '5.3-maint'

Revised supported site classes and bounds

See merge request !107

model-info.json

 {
   "name": "NSHM Conterminous U.S. 2018",
   "site-class-vs30": {
-    "A": 3000,
     "AB": 1500,
     "B": 1080,
     "BC": 760,
@@ -12,7 +11,7 @@
     "E": 150
   },
   "bounds": {
-    "min-latitude": 24.6,
+    "min-latitude": 24.4,
     "min-longitude": -125.0,
     "max-latitude": 50.0,
     "max-longitude": -65.0