Refactoring validator spec

[gracekarina]

Validating 2.0 and 3.0.X

• Remove YAML responses, it should only return JSON
• Change / in the response, to JSON.
• Both by URL and by content return either an image or a JSON
• adding format: binary to the image shema
• The JSON/YAML/IMAGE objects were written once under the components and reused across the definition.
• Fix typo in the word 'invaild' - should be 'invalid'

[JonathanParrilla]

please build

[frantuma]

replaced by #133