Add support for OpenAPI in compendium

[pirita]

Add support for OpenAPI in compendium

[pepegar]

openapi is already supported by skeuomorph, although not thoroughly tested. I think that the integration in compendium should be easy.

[Yawolf]

Is this the same as #99?

[JesusMtnez]

@mrtmmr what is the status on this one? Are all pieces ready to support OpenAPI ?

[ememmr]

No, @JesusMtnez , it was on development but I had to stop to prioritize other issues. I guess this will disappear when we merge compendium plugin with mu plugin. If not I'll put an eye on it