[ruby/io-console] Bump up v0.8.0.beta1

https://github.com/ruby/io-console/commit/8ec27d403e

ext/io/console/console.c

@@ -4,7 +4,7 @@
  */
 
 static const char *const
-IO_CONSOLE_VERSION = "0.7.2";
+IO_CONSOLE_VERSION = "0.8.0.beta1";
 
 #include "ruby.h"
 #include "ruby/io.h"