Function get_rate is not accessible from Ups() object

I was trying to run code from read.me but this link `$rate = $Ups->get_rate($destination, $packages);`
returns NULL all the time.

It looks like get_rate function is not accessible from Ups object and you have to call it through `rates` property of the UPS object`$Ups->rates->get_rate($packages);`

Probably README example is just not updated?

`
