Cleanup.
docs.
Removed session_test.go.
Refactored the code.

api.go provides sdk to access UPR streams.
session.go is vastly simplified to,
  - avoid duplex support in UPR connections.
  - if an error occurs in one stream or connection, all connections are closed
    and restarted from the last received seqeunce number for the feed.
upr.go
  code refactoring.
Local unit testing for upr transport protocol.
Removed `startclient` example
Added 3 examples files.

- to get failover logs for all vbuckets.
- to start a feed and collect for mutations.
- to restart a feed from know sequence number.
Go format.
go formating
Goformating.