mutate 'biological_context.name' filters for mongo
mutate 'biological_context.name' filters for mongo

mongo persists biological_context elements as {name: "", value: ""}
objects; this change mutates biological_context filters to use the
$elemMatch operator.

OpenBEL/openbel-server,OpenBEL/openbel-server,OpenBEL/openbel-server,OpenBEL/openbel-api,nbargnesi/openbel-server,OpenBEL/openbel-api,nbargnesi/openbel-server,OpenBEL/openbel-api,OpenBEL/openbel-api,nbargnesi/openbel-server