0.7.1: Enhancing the Qiblah struct

The Qiblah struct now implements the Debug and Display traits that can be used for printing out the value of the Qiblah. The struct also gained a new method, value() for getting the f64 value of the direction. Also updating test to use the public interface and adding a new test to assert the display value of the Qiblah direction.

🎩-tip to @TheCodeHeist for bringing the issue to my attention.