Solved problem while two adding percentage condition.

[himu3355]

I just updated getTotal() method.
I have a problem while added two percentage conditions. Ex.
One for tax

$condition1 = new \Darryldecode\Cart\CartCondition(array(
	'name' => 'GST',
	'type' => 'GST',
	'target' => 'total',
	'value' => '5%',
	'attributes' => array( // attributes field is optional
		'description' => 'Value added tax'
	)
));

And another one for coupon

$condition2 = new \Darryldecode\Cart\CartCondition(array(
	'name' => 'COUPON',
	'type' => 'COUPON',
	'target' => 'total',
	'value' => '-10%',
	'attributes' => array( // attributes field is optional
		'description' => 'Value added tax'
	)
));

Applying these two conditions, the result is very strange.
I think it's work in my pull request.
and I hope it doesn't affect other results.