Provide inkeeper api definition to twintip

[jukey]

Description:

Twintip crawls for API definitions for applications registered at Kio. Please make the Innkeeper API definition available via twintip.

Ressources:

• See Twintip documentation
• Innkeeper swagger definition file
• Zalando central swagger repository

[lasomethingsomething]

@jukey @danpersa @fmueller Can we close this issue, in light of its age + changes to Twintip made since then?

[jukey]

This issue is still valid.