OpenStack Cinder cleanup

This PR cleans up line endings and formats json using [jsonlint](jsonlint.org). It also eliminates the deprecated [`StringPayload`](https://github.com/jclouds/jclouds/blob/master/core/src/main/java/org/jclouds/io/Payloads.java#L53) in favor of [`ByteSourcePayload`](https://github.com/jclouds/jclouds/blob/master/core/src/main/java/org/jclouds/io/Payloads.java#L51) in the `SnapshotApiExpectTest`