Typo in JSON-LD context for IIIF Authentication API 1.0 (and the draft version)

[lutzhelm]

The JSON-LD context files for IIIF Authentication API 1.0 and the draft version of the API both contain a typo, failureDescriptiom instead of failureDescription:

api/source/auth/1/context.json

Lines 33 to 35 in 17629e1

	"failureDescription": {
	"@id": "auth:failureDescriptiom"
	}

api/source/auth/0/context.json

Lines 33 to 35 in 17629e1

	"failureDescription": {
	"@id": "auth:failureDescriptiom"
	}