Test the algorithm and more

[jiapivialiu]

We need the ADMM algorithm to be tested to make sure that it works and is numerically stable in each scenario. Here are a few scenarios that are worth being considered:

• easy inputs (say, current_counts with two segments, short lengths (e.g., including less than 10 signals), and low variation) and difficult inputs (say, current_counts with more than 5 segments, long lengths, and large variation);
• small lambdas (lambda = 0) and large lambdas (say, lambda > 10);
• low degrees (say, degree = 0,1,2,3) and high degrees (say, degree > 3).

We also need other functions (including generate_D and get_mu) to be tested in various scenarios.

[zcaiElvis]

Working on generate_D and get_mu, will move up to admm_solver.