* Added implementation for random_gamma op.
* Added implementation for random_poisson op and support classes.
* Added helpers for random_poisson and random_gamma ops.
* Implementation of random_poisson. The first working edition.
* Implementation of random_poisson. Parallelized working edition.
* Implementation of random_gamma. Parallelized working edition with alpha only.
* Added cuda implementation for helper of poisson distribution.
* Corrected shape calculation with random_gamma and tests.
* Finished cpu implementation for gamma distribution.
* Finished cuda implementation for random_gamma op.
* Refactored cpu helpers for random_gamma and random_poisson ops.
* Refactored cuda helpers for gamma and poisson distribution.
* Refactored cuda helper for gamma distribution.
* Refactored cpu helper for random_poisson op.
* Refactored cpu helper for random_gamma op.
shugeo