Adds util to ImgurAuth to authorise requests with client id

- The test added fails - it's unable to set properties on an open connection
- I'm unsure how it's different from: https://github.com/talklittle/ImgurAPIv3ExampleAndroid/blob/master/ImgurAPIv3Example/src/main/java/com/imgur/api3example/login/ImgurAuthorization.java#L86, which works