add check isMentionMe method

[bitwater]

add check isMentionedMe method

[√] Feature

Checklist

Description

Does this PR introduce a breaking change?

[√] No

[bitwater]

Oh， all failed

[lijiarui]

@bitwater Why did you close this pr? I think this function may necessary thought the function name is not that appropriate.

[bitwater]

@lijiarui How about isMentionMe？zixia suggest me send a Pull Request to add it to the library

[bitwater]

Sorry, need more test

[bitwater]

Why is appveyor that error ?

Error: listen EADDRINUSE 127.0.0.1:10513
    at Server.setupListenHandle [as _listen2] (net.js:1335:14)
    at listenInCluster (net.js:1383:12)
    at doListen (net.js:1509:7)
    at process._tickCallback (internal/process/next_tick.js:63:19)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR!

[huan]

This new method of Message class will be very useful, thank you very much for the contribution!