version appears to be incorrect

[sslupsky]

Hi, I was browsing the source code while evaluating CmdMessager and noticed the following inconsistency with the README Changelog:

Arduino-CmdMessenger/CmdMessenger.cpp

Line 51 in 8c3c444

#define _CMDMESSENGER_VERSION 3_6 // software version of this library

As you can see, CmdMessenger.cpp in the master branch shows version 3_6. However, the Changelog indicates the version is "CmdMessenger v4.0.0".