Update dependencies request and request-promise ... all tests passed

## Motivation
- Some upstream projects that use `vend-nodejs-sdk` were facing strange
issues where long-running use (after 47 minutes or so) led so a situation
where nodejs would just hang after a POST request.
- There weren't any clear CPU or Memory consumption red flags.
- It seemed more like a bad promise chain or failing to invoke a callback
that often leads nodejs into a forever running state and there's nothing
really going on.

## Solution
Look at the [CHANGELOG](https://github.com/request/request/blob/master/CHANGELOG.md)
for `request` and see if any plausible reasons for trying a module update.

1. request/request#2431
2. request/request#2414
3. request/request#2447
4. request/request#2448

This wasn't an exact science but their descriptions seemed to merit
the dependency upgrade as "at least worth a try"

## Consequences
Dropped support for Node 0.10
request/request#2381

package.json

@@ -56,7 +56,8 @@
     "bluebird": "2.6.0",
     "moment": "2.9.0",
     "nconf": "0.7.1",
-    "request-promise": "0.3.2",
+    "request": "2.81.0",
+    "request-promise": "4.2.1",
     "underscore": "1.7.0",
     "winston": "0.9.0"
   },