Update dependency on request to address ReDoS

Latest version of `request` pulls in `tough-cookie` which recently address a ReDoS vulnerability: salesforce/tough-cookie#92

Author: dancrumb

Diff for: package.json

@@ -24,7 +24,7 @@
     "nopt": "^4.0.1",
     "npmlog": "^4.0.2",
     "rc": "^1.1.7",
-    "request": "2.81.0",
+    "request": "2.83.0",
     "hawk":"3.1.3",
     "rimraf": "^2.6.1",
     "semver": "^5.3.0",