Add zipkin-blobs support

Other than some code refactoring, this release contains zipkin support. Brave span can now be used as SpanBlobContext to set request/response tags.

Use OT Span

This change updates SpanBlobContext to use OpenTracing span object for add a tag for Blob. It allows the library to be used by other OT clients.

Added STS Assume role for S3Dispatcher

This release brings the use of AWS STS assume-role in S3Dispatcher for blobs in haystack.

Deployment scripts added and "exported port" changed for http-reverse-proxy docker image

Added kubernetes deployment scripts for reverse-proxy and also changed the exposed port for reverse proxy from 34002 to 35002 for its docker image.

Renaming the name of BlobAgent for config

This is the minor update that will return the name of BlobAgent as ossblobs in place of blobs.

First blobs release

This is the initial release for haystack blobs and pushing them to various sinks including haystack-agent.
For more details please refer README for complete information.