Bump handlebars from 4.2.0 to 4.2.1 in /build

Bumps [handlebars](https://github.com/wycats/handlebars.js) from 4.2.0 to 4.2.1.
- [Release notes](https://github.com/wycats/handlebars.js/releases)
- [Changelog](https://github.com/wycats/handlebars.js/blob/v4.2.1/release-notes.md)
- [Commits](https://github.com/wycats/handlebars.js/compare/v4.2.0...v4.2.1)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

build/package-lock.json

@@ -2079,9 +2079,9 @@
       "dev": true
     },
     "handlebars": {
-      "version": "4.2.0",
-      "resolved": "https://registry.npmjs.org/handlebars/-/handlebars-4.2.0.tgz",
-      "integrity": "sha512-Kb4xn5Qh1cxAKvQnzNWZ512DhABzyFNmsaJf3OAkWNa4NkaqWcNI8Tao8Tasi0/F4JD9oyG0YxuFyvyR57d+Gw==",
+      "version": "4.2.1",
+      "resolved": "https://registry.npmjs.org/handlebars/-/handlebars-4.2.1.tgz",
+      "integrity": "sha512-bqPIlDk06UWbVEIFoYj+LVo42WhK96J+b25l7hbFDpxrOXMphFM3fNIm+cluwg4Pk2jiLjWU5nHQY7igGE75NQ==",
       "dev": true,
       "requires": {
         "neo-async": "^2.6.0",

build/package.json

@@ -11,7 +11,7 @@
   "contributors": [],
   "dependencies": {},
   "devDependencies": {
-    "handlebars": "^4.2.0",
+    "handlebars": "^4.2.1",
     "jasmine-core": "~2.5.2",
     "jasmine-sinon": "^0.4.0",
     "jsdoc": "^3.6.3",