Update algorithm tutorials

[dmdunla]

Following the work in #444, update the following tutorials:

• docs/source/tutorial/algorithm_cp_als.ipynb
• docs/source/tutorial/algorithm_cp_apr.ipynb
• docs/source/tutorial/algorithm_gcp_opt.ipynb
• docs/source/tutorial/algorithm_hosvd.ipynb
• docs/source/tutorial/algorithm_tucker_als.ipynb
• docs/source/tutorial/utility_test_problem.ipynb