fix: package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/npm:cryptiles:20180710
- https://snyk.io/vuln/npm:extend:20180424
- https://snyk.io/vuln/npm:stringstream:20180511

package.json

@@ -71,7 +71,7 @@
     "no-case": "^2.3.2",
     "promise-queue": "^2.2.5",
     "qs": "^6.5.1",
-    "request": "^2.85.0",
+    "request": "^2.87.0",
     "requestretry": "^1.13.0"
   },
   "devDependencies": {