assert_covers treats arrays as maps

[locker]

assert_covers should treat arrays as scalars, i.e. never assume that one array may cover another unless they are equal. For example, the following assertions must fail while currently they pass:

t.assert_covers({1, 2, 3}, {1, 2})
t.assert_covers({a = {1, 2, 3}}, {a = {1, 2}})