Potential race condition in service initialization code

[jsdelfino]

See background in issue #197 in particular this code section:
https://github.com/cloudfoundry-incubator/cf-abacus/blob/master/lib/aggregation/aggregator/src/index.js#L531

The service could potentially accept requests before the OAuth token initialization completes.

[cf-gitbot]

We have created an issue in Pivotal Tracker to manage this. You can view the current status of your issue at: https://www.pivotaltracker.com/story/show/116891525.