Remove axios from dependencies (fixes SumoLogic#78)

- Was replaced with SuperAgent
- Due to vulnerability CVE-2019-10742 causing package managers and github to trigger a security alert
- See issue SumoLogic#78 for details

package.json

@@ -13,7 +13,7 @@
     "prepublishOnly": "npm run build"
   },
   "dependencies": {
-    "axios": "^0.18.0",
+    "axios": "^0.19.0",
     "superagent": "^5.0.5"
   },
   "devDependencies": {