Fix dependency on sinon packages

Moves sinon-related packages to devDependencies. Additionally downgrades sinon to ~1.7.3 which is known to work with node v0.10.x services.

Extra HTTP Headers for Tracking Data Producer

Added extra headers for data producer. We hope to capture the below 3 types of information:

1. Service Name
2. Client Version (language and version number)
3. Instance Name (for a service with multiple running instances, which instance it is coming from

By default they will be fetched automatically, no extra work is needed.
The Service Name by default is retrieved from environment variable UDEPLOY_APP_ID.
The Instance Name by default is retrieved from environment variable UDEPLOY_DEPLOYMENT_NAME
The client version is generated by library.

The headers and values are also customizable. Below are the options field to customize them:

Category	Value	HTTP Header Name	Retrieve from Env Var
Service Name	options.serviceName	options.serviceNameHeader	options.serviceNameEnv
Instance Name	options.instanceName	options.instanceNameHeader	options.instanceNameEnv
Client Version	(N.A.)	options.clientVersionHeader	(N.A.)