Prepare version 1.16.0

Bump the version number and update search-core

J=BACK-2236
TEST=manual

Ran a build an confirmed a test site worked with EU and
the EU builds

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@yext/answers-search-ui",
-  "version": "1.15.5",
+  "version": "1.16.0",
   "description": "Javascript Search Programming Interface",
   "main": "dist/answers-umd.js",
   "repository": {
@@ -30,7 +30,7 @@
     "@mapbox/mapbox-gl-language": "^0.10.1",
     "@yext/answers-storage": "^1.1.0",
     "@yext/rtf-converter": "^1.7.1",
-    "@yext/search-core": "^2.3.0-beta.1",
+    "@yext/search-core": "^2.3.0",
     "bowser": "^2.11.0",
     "cross-fetch": "^3.1.5",
     "css-vars-ponyfill": "^2.4.3",