Removed superfluous `do`
Removed superfluous `do`

See https://github.com/marick/Midje/pull/228#discussion-diff-5308658 and
the following thread for reference.

* src/midje/emission/plugins/tap.clj:

Signed-off-by: giorgio-v <3a4d67eb2c7c1aeb8cfd15182af01f6f7ec0be3d@refactor.it>

bens/Midje,marick/Midje,yfractal/Midje,aeriksson/Midje