Use the OpenTok SDK for ping.

On the topic of package.json and versions, not sure if we want to update any of these modules. Let me know and I can file a GitHub or Bugzilla bug.

### Outdated Dependencies

- (minor) **cors** (package: 2.3.1, latest: 2.4.1)
- (patch) **hiredis** (package: 0.1.16, latest: 0.1.17)
- (minor) **raven** (package: 0.6.3, latest: 0.7.0)
- (minor) **redis** (package: 0.10.3, latest: 0.11.0)
- (minor) **request** (package: 2.36.0, latest: 2.37.0)
- (patch) **statsd-node** (package: 0.2.2, latest: 0.2.3)
- (patch) **strftime** (package: 0.8.0, latest: 0.8.1)

### Outdated Dev Dependencies

- (minor) **sinon** (package: 1.9.x, latest: 1.10.3)
- (?????) **superagent-hawk** (package: git://github.com/CrowdProcess/superagent-hawk.git#69ee9c, latest: 0.0.3)
- (minor) **supertest** (package: 0.10.x, latest: 0.13.0)