CDRIVER-3401 add insert to stepdown tests
CDRIVER-3401 add insert to stepdown tests

beingmeta/mongo-c-driver,jmikola/mongo-c-driver,rcsanchez97/mongo-c-driver,beingmeta/mongo-c-driver,rcsanchez97/mongo-c-driver,beingmeta/mongo-c-driver,rcsanchez97/mongo-c-driver,beingmeta/mongo-c-driver,rcsanchez97/mongo-c-driver,mongodb/mongo-c-driver,mongodb/mongo-c-driver,mongodb/mongo-c-driver,rcsanchez97/mongo-c-driver,jmikola/mongo-c-driver,mongodb/mongo-c-driver,beingmeta/mongo-c-driver,mongodb/mongo-c-driver,jmikola/mongo-c-driver,rcsanchez97/mongo-c-driver,mongodb/mongo-c-driver,rcsanchez97/mongo-c-driver,beingmeta/mongo-c-driver,mongodb/mongo-c-driver,jmikola/mongo-c-driver,jmikola/mongo-c-driver,jmikola/mongo-c-driver,jmikola/mongo-c-driver,beingmeta/mongo-c-driver,beingmeta/mongo-c-driver