Implement generators

[gregberge]

Implement a new command shipit --init that will generate an empty shipitfile:

module.exports = shipit => {
  shipit.initConfig({
    default: {},
    production: {
      servers: 'deploy@myserver.com',
    },
  })

  shipit.task('hello', () => shipit.remote('echo "hello"'))
}

Original idea from @halfdan in #75

[utkarsh-dixit]

I'd like to work on this. @neoziro Does this generator needs to be interactive? I was thinking it would be a good idea if the user can create and setup shipit configuration using generator without any need to edit the file.

[gregberge]

Hello @utkarsh-dixit, yes interactive is a good idea! Like npm init.