[feature] add configuration to /api/v1/instance response (#670)

* add configuration object to api instance model

* regenerate swagger docs

* add func to return all supported mimes for media

* add instance configuration to api serialization

* fix json tags

* update instance endpoint tests

* fix typeutils tests

* final regen of swagger docs

* omitempty instance configuration

internal/media/util.go

@@ -26,6 +26,16 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
+// AllSupportedMIMETypes just returns all media
+// MIME types supported by this instance.
+func AllSupportedMIMETypes() []string {
+	return []string{
+		mimeImageJpeg,
+		mimeImageGif,
+		mimeImagePng,
+	}
+}
+
 // parseContentType parses the MIME content type from a file, returning it as a string in the form (eg., "image/jpeg").
 // Returns an error if the content type is not something we can process.
 //