function bytes(value, type) {
  return value * Math.pow(2, (['KB','MB','GB','TB','PB','EB','ZB','YB'].indexOf(type) + 1) * 10);
}
Returns the number of bytes for a given value of type.

@static
@memberOf _
@category Array
@param {Number} value - The value.
@param {string} type - The type of the value.
@returns {Number} Returns the number of bytes.
@example

_.bytes(10, 'MB');
// => 10485760

_.bytes(1, 'TB');
// => 10995116277760

_.bytes(15, 'KB');
// => 15360

_.bytes(1, 'YB');
// => 1.8133887294219438e+25