Remove server/client

[david4096]

The server and client in this repo are aspirational and should be removed and replaced with the workflow-service's server and client, or a simpler demo server should be provided for creating progress on the schemas.

https://github.com/ga4gh/workflow-execution-service-schemas/blob/develop/python/ga4gh/wes/controllers.py

https://github.com/common-workflow-language/workflow-service

[jaeddy]

I vote we go with option B:

a simpler demo server should be provided for creating progress on the schemas

(or something like it)

Will add this to the TODO list for v1.1.