fix(package): update jsonwebtoken to version 8.0.1

Closes #58

Author: greenkeeper[bot]

package.json

@@ -20,7 +20,7 @@
     "express": "^4.14.0",
     "formidable": "~1.1.1",
     "http": "0.0.0",
-    "jsonwebtoken": "^7.2.1",
+    "jsonwebtoken": "^8.0.1",
     "jwks-utils": "^1.0.5",
     "jws-jwk": "^0.1.4",
     "mammoth": "^1.3.1",