#53, and use transformed value directly

[sneurlax]

@serhack , this is a variation upon https://github.com/monero-integrations/monerophp/commit/39c14dcc8b14de0b01e8bbfc30a21e83a06794c2 wherein transformed values are used directly: so instead of

$new_amount = $this->_transform($amount);
$params = array('amount' => $new_amount ... )

it is just

$params = array('amount' => $this->_transform($amount) ... )

It is up to your preference how to do it, really. This is based on https://github.com/monero-integrations/monerophp/pull/53 so merging this will merge in that

Closes #53