fix: .snyk & package.json to reduce vulnerabilities

The following vulnerabilities are fixed with a Snyk patch:
- https://snyk.io/vuln/SNYK-JS-LODASH-450202

package.json

@@ -15,13 +15,17 @@
     "popper.js": "^1.15.0",
     "underscore": "^1.9.1",
     "vis": "^4.21.0",
-    "webpack-merge": "^4.1.4"
+    "webpack-merge": "^4.1.4",
+    "snyk": "^1.189.0"
   },
   "devDependencies": {
     "webpack-dev-server": "3.4.1"
   },
   "scripts": {
     "webpack": "./bin/webpack",
-    "webpack-dev-server": "./bin/webpack-dev-server"
-  }
+    "webpack-dev-server": "./bin/webpack-dev-server",
+    "snyk-protect": "snyk protect",
+    "prepublish": "npm run snyk-protect"
+  },
+  "snyk": true
 }