optionsToArray(obj, optionsPrefix, hasEquals) {
      optionsPrefix = optionsPrefix || '--'
      var ret = []
      Object.keys(obj).forEach((key) => {
        ret.push(optionsPrefix + key + (hasEquals ? '=' : ''))
        if (obj[key]) {
          ret.push(obj[key])
        }
      })
      return ret
    }
Convert an options object into a valid arguments array for the child_process.spawn method
from:
  var options = {
    foo: 'hello',
    baz: 'world'
  }
to:
  ['--foo=', 'hello', '--baz=','world']

@param   { Object }  obj - object we need to convert
@param   { Array }   optionsPrefix - use a prefix for the new array created
@param   { Boolean } hasEquals - set the options commands using the equal
@returns { Array } - options array