Fix typo in README about client transport option "rocket" instead of "rsocket".
Fix typo in README about client transport option "rocket" instead of "rsocket".

Summary: It is mentioned throughout the README that client supports a transport option as "rsocket", while the code `util/Util.h:113` references it as "rocket". Fixing this typo in README.

Reviewed By: vitaut

Differential Revision: D24594949

fbshipit-source-id: a598096122c1377c39adb0f5b0ddb07357408885

facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift