GET /schemas/{schema_id} models say a "schema_json" object is returned when actually "schema" is returned

[jcourt562]

The swagger api and code generated via codegen provides an interface expecting a "schema_json" object returned from "GET /schemas/{schema_id}". In fact the body in the response returns a "schema" object. This makes it difficult in many languages to access the data returned. Suggest that the swagger I/f change to "schema" since that is what working client code must be using to access the data. The response body coming back from a running ACA-py v0.5.3 is :

{"schema": {"ver": "1.0", "id": "FfTM7q3uZLipmQnXjghcbZ:2:University_Transcript:0.1", "name": "University_Transcript", "version": "0.1", "attrNames": ["first_name", "last_name"], "seqNo": 8}}

I have submitted a one line pull request to fix this.

[sklump]

#674 addresses.