upgrade lodash to >=4.17.12 to address security alert

Author: samdengler

website/package.json

@@ -11,7 +11,7 @@
     "gulp-autoprefixer": "~3.0.2",
     "gulp-angular-templatecache": "~1.8.0",
     "del": "~2.0.2",
-    "lodash": "~3.10.1",
+    "lodash": ">=4.17.12",
     "gulp-cssnano": "~2.1.1",
     "gulp-filter": "~3.0.1",
     "gulp-flatten": "~0.2.0",