Introduce tests for POST Verification

Added tests that allow for the veriication of POST requests. Headers and body can be verified through the internal DSL.
Introduce tests for DELETE Verification

Added tests that allow for the verification of DELETE requests. Headers
can be verified through the internal DSL. Body verification will throw
exception.
Introduce tests for HEAD Verification

Added tests that allow for the verification of HEAD requests. Headers
can be verified through the internal DSL. Body verification will throw
exception.
Introduce tests for OPTIONS Verification

Added tests that allow for the verification of OPTIONS requests. Headers
can be verified through the internal DSL. Body verification will throw
exception.
Introduce tests for TRACE Verification

Added tests that allow for the verification of TRACE requests. Headers
can be verified through the internal DSL. Body verification will throw
exception.
Simplify non-bodied requests

Simplified code to only make use of a generic class to handle request
types that do not support body playloads (entities).
Introduce CortX reset

Added Cortx method to allow users to reset CortX server registry.
Includes endpoint, DSL method and respective tests.
Update verify documentation
Introduce Retrieve tests

Added unit tests to verify the implementation of DSL client Retrieve functionality.
Introduce Request Response Registration DSL

Introduced DSL support for get/put/post/delete/head/options/trace header and body retrival.

Issue #4
Merge pull request #6 from crazyfrozenpenguin/dsl_tests

Client DSL