Add array of commands in exec

[isRuslan]

Hi everyone.
I suggest to add possibility to set array of commands in first argument of exec method.
Example:

shell.exec(['git pull', 'npm i'], function(code, output) {

});

Fixes #103

[isRuslan]

👀

[ariporad]

@nfischer: What are your thoughts? I'm not so sure about this.

[nfischer]

I vote to close this. I think Array.join(';') is good enough for most users

[ariporad]

Me too. Closing.

[ariporad]

@isRuslan: Thanks so much for your PR, but unfortunately we're going to have to close this. It's just a very strange use-case, and [command1, command2, ...commandN].join(';') should really work for most cases. Thanks!