Previously the mongodb dbtests and unittests were only built, and not actually
run.
* gnu/packages/databases.scm (mongodb)[native-inputs]: Add python2-minimal,
python2-pymongo and python2-pyyaml for running the resmoke.py program, and
add tzdata as some tests fail without this.
[arguments]: Run the tests through the resmoke.py script in the check phase,
set TZDIR as a couple of tests seem to depend on this, add a comment about
the resource requirements of the tests, as they require a large amount of
disk space, and disable the async_stream_test, as it seems to hang.
90205b625e