dsh_api build helpers

This lib crate contains functions that are needed during the build phase of the dsh_api crate.

• Generate the generic client code
• Generate Progenitor client from an openapi specification
• Update the openapi specification

It has no real value in any other situation. It is published to crates.io because the current capabilities of the rust build.rs system are too limited for complex build strategies.

lib.rs:

Helper functions for the build phase of the dsh_api crate.

• Generate the generic client code
• Generate Progenitor client from an openapi specification
• Update the openapi specification