message: fixed version description
  fixed version description
diff: @@ -192,9 +192,9 @@ By using Swoole, you can build enhanced web applications with more control, real
  ## Requirements
  -* Version-1: PHP 5.3.10 or later
  -* Version-2: PHP 7.0.0 or later
  -* Version-4: PHP 7.0.0 or later
  +* Version 1.x: PHP 5.3.10 or later
  +* Version 2.x: PHP 7.0.0 or later
  +* Version 4.x: PHP 7.0.0 or later
  * Linux, OS X and basic Windows support (thanks to CygWin)
  * GCC 4.4 or later
  * GCC 4.8 or later (Version >= 4)
  