port mongo driver to event emitter

Signed-off-by: Niv Sardi <xaiki@evilgiggle.com>
update tests for mongo driver (event emitter)

Signed-off-by: Niv Sardi <xaiki@evilgiggle.com>
port json driver to event emitter

Signed-off-by: Niv Sardi <xaiki@evilgiggle.com>
whitespaces

Signed-off-by: Niv Sardi <xaiki@evilgiggle.com>