fix: package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-JQUERY-174006

package.json

@@ -61,7 +61,7 @@
     "file-type": "^11.0.0",
     "github-api": "^3.0.0",
     "hammerjs": "^2.0.8",
-    "jquery": "^3.1.1",
+    "jquery": "^3.4.0",
     "lodash": "^4.17.11",
     "mime-types": "^2.1.14",
     "moment": "^2.18.1",