Bump handlebars from 4.7.6 to 4.7.7 (#6)

Author: dependabot[bot]

package-lock.json

@@ -13,7 +13,7 @@
     "debug": "^4.3.1",
     "express": "^4.17.1",
     "express-handlebars": "5.2.0",
-    "handlebars": "^4.7.6",
+    "handlebars": "^4.7.7",
     "mongoose": "^5.11.14",
     "morgan": "^1.10.0",
     "postcss": "^8.2.6",