Promisified espeak

This is a simple wrapper of the Linux application espeak, used to text-to-speech. It has a Promise based api and the availables methods are:

say(text, opts)

Calls espeak using the text passed on the first parameters and include any additional arguments passed on the second parameter

male1, male2, male3, male4, male5, male6 and male7

It's exactly the same as the say method but use one of espeak's male default voice

female1, female2, female3, female4, female5

It's exactly the same as the say method but use one of espeak's female default voice