Transitions between slides don't work in Safari

[ui-matt]

Issue desc:

Defining an option to set the speed or leaving blank to use the default speed: 300 should allow the animate when toggling the active slide but doesn't work in Safari.

Non Safari browser result:

Adds transition-duration: 0.3s; to targeted element that becomes active to allow for the transition to take effect.

Safari browser result:

Doesn't add any transition-duration to the styles resulting in no animation and inherits the base css style below:

.tns-slider {
	transition: all 0s;
}

Temp workaround:

Setting a transition-duration on the element through css instead of relying on the speed option.