Made http-request rely on 1.3.6

package.json

@@ -35,7 +35,7 @@
     "forever-agent": "~0.6.1",
     "form-data": "~2.3.2",
     "har-validator": "~5.1.3",
-    "http-signature": "~1.3.0",
+    "http-signature": "~1.3.6",
     "is-typedarray": "~1.0.0",
     "isstream": "~0.1.2",
     "json-stringify-safe": "~5.0.1",