Merge pull request #68 from pmohan6/master

Updating sdk dependency and minor bug fix
A few updates for default activity registration options.
Merge pull request #71 from pmohan6/master

Bumping version to 2.1.0 and multiple bug fixes.
Merge pull request #72 from pmohan6/master

Adding WorkflowReplayer and bumping version to 2.2.0
Merge pull request #73 from pmohan6/master

fixing file requirements for replayer and bumping version
Documentation updates for the Replayer
Merge pull request #74 from awsdocs/doc_updates

Documentation updates for the Replayer
Merge pull request #75 from awsdocs/eron_updates

A few updates for default activity registration options.