Investigate results of cargo mutant testing

[cwkingjr]

gift_circle % cargo mutants
Found 55 mutants to test
ok Unmutated baseline in 14.2s build + 0.3s test
INFO Auto-set test timeout to 20s
MISSED src/main.rs:44:5: replace main with () in 0.7s build + 0.3s test
MISSED src/gift_circle.rs:119:23: replace += with *= in get_gift_circle in 0.7s build + 0.3s test
MISSED src/gift_circle.rs:30:74: replace > with == in generate_group_path in 0.6s build + 0.3s test
MISSED src/people.rs:64:45: replace * with + in ::has_possible_hamiltonian_path in 0.6s build + 0.3s test
MISSED src/gift_circle.rs:30:69: replace * with / in generate_group_path in 0.6s build + 0.3s test
MISSED src/people.rs:105:52: replace && with || in ::is_valid_gift_circle in 0.6s build + 0.3s test
MISSED src/gift_circle.rs:78:26: replace <= with > in get_gift_circle in 0.6s build + 0.3s test
TIMEOUT src/gift_circle.rs:11:30: replace != with == in move_person in 0.6s build + 20.1s test
MISSED src/gift_circle.rs:115:34: replace == with != in get_gift_circle in 0.7s build + 0.3s test
MISSED src/gift_circle.rs:30:74: replace > with < in generate_group_path in 0.6s build + 0.3s test
MISSED src/people.rs:32:60: replace + with * in ::assign_gift_recipients in 0.6s build + 0.3s test
MISSED src/gift_circle.rs:62:11: delete ! in generate_no_group_path in 0.6s build + 0.3s test
MISSED src/gift_circle.rs:30:69: replace * with + in generate_group_path in 0.6s build + 0.3s test
TIMEOUT src/gift_circle.rs:11:5: replace move_person with () in 0.7s build + 20.0s test
MISSED src/gift_circle.rs:122:22: replace == with != in get_gift_circle in 0.7s build + 0.3s test
MISSED src/person.rs:23:9: replace Person::new_no_group -> Self with Default::default() in 0.6s build + 0.3s test
MISSED src/gift_circle.rs:104:30: replace && with || in get_gift_circle in 0.6s build + 0.3s test
MISSED src/gift_circle.rs:60:5: replace generate_no_group_path -> People with Default::default() in 0.6s build + 0.3s test
MISSED src/main.rs:20:5: replace run -> Result<()> with Ok(()) in 0.9s build + 0.3s test
MISSED src/people.rs:105:9: replace ::is_valid_gift_circle -> bool with true in 0.7s build + 0.3s test
55 mutants tested in 1m 43s: 18 missed, 32 caught, 3 unviable, 2 timeouts