Adapting test_add_party.

[toufic0710]

Hi,

I want to modify the test_add_party test to change n, t and the number of people who are willing to do a resharing. For example, I have an error when I try to modify 5 by 4 here :

fs-dkr/src/test.rs

Line 157 in 6a5b495

let mut keys = all_keys[0..5].to_vec();

---- test::tests::test_add_party stdout ---- thread 'test::tests::test_add_party' panicked at 'insertion index (is 6) should be <= len (is 5)', library/alloc/src/vec/mod.rs:1445:13

I have the same kind of error when I try to modify t from 7 to 8 for example (but it works for 6...).

would appreciate insights!