Test failure due to missing sr_state_free[_all]() in shared-random unit tests

It looks like Travis recently upgraded to a clang with a (better) LeakSanitizer.

The following tests have memory leaks:

• shared-random/vote
• shared-random/sr_compute_srv
• shared-random/state_transition

They are missing a call to sr_state_free() in 0.2.9 and later. But it's spelt sr_state_free_all() in 0.3.3 and later.