* Added volume of a torus
Added function calculation the volume of a torus according to the formula:
V = 2 * pi^2 * R * r^2
where R is the major radius and r is the minor radius of the torus.
* Added test for torus volume
* Added volume of a pyramid frustum
Added a function calculating volume of a pyramid frustum, V=(S1+S2+sqrt(S1*S2))*h/3
* compiler error fixed
* Added pyramid frustum test case
* extra space removed
* Add Function volumeFrustum To Calculate Frustum Of Cone Then Test It.
* Add Function volumeFrustumOfCone To Calculate Frustum Of Cone Then Test It.
* Update VolumeTest.java
* Update Volume.java
* Fixed functions and removed main() in Volume.java
Fixed calculation errors in volumeSphere() and volumeHemisphere() functions and removed main() and changed functions access specifier from private to public
* Created VolumeTest.java
Created VolumeTest.java JUnit Tests for Volume.java
Co-authored-by: Debasish Biswas <debasishbsws.abc@gmail.com>
