package: Update the 'handlebars' (#1883)

Update it to the latest version and 'package-lock.json' is updated
automatically.

Author: Maledong

package-lock.json

@@ -34,7 +34,7 @@
     "autoprefixer-stylus": "0.14.0",
     "cheerio": "0.22.0",
     "chokidar": "^2.0.4",
-    "handlebars": "4.0.11",
+    "handlebars": "4.0.12",
     "jstransformer-handlebars": "1.1.0",
     "junk": "2.1.0",
     "lodash.defaultsdeep": "4.6.0",