Binary feature
I see that your library missing binary feature.
Here a little cheatsheet for enabling binary.

Binary message bypass UTF-8 checking.
You'll need to have 2 variables : 
CurrentFrameOpcode 
FirstFrameOpcode ( when frame opcode are 0 to know if your messsage are TEXT or BINARY )

Add event ->onBinary ( seem better for dev user ) or 
add opcode in ->onMessage

Your send method are allready well formed for sending binary ( last variable )
