test(bitswap)

@whyrusleeping This appears to be a timing issue. The asynchronous
nature of the new structure provides has the bitswap waiting on the
context a bit more. This isn't a problem at all, but in this test, it
makes the functions return in an inconveniently timely manner.

TODO don't let the test depend on time.

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>