message: Test only with replica sets on Evergreen
  Switch from standalone to replica set in order to test change streams. Later
  we'll test against a variety of topologies.
diff: @@ -120,6 +120,7 @@ functions:
  export MONGODB_BINARIES=$DRIVERS_TOOLS/mongodb/bin
  export MONGO_ORCHESTRATION_HOME=$DRIVERS_TOOLS/.evergreen/orchestration
  export MONGODB_VERSION=${mongodb_version}
  + export TOPOLOGY=replica_set
  echo "{ \"releases\": { \"default\": \"$MONGODB_BINARIES\" }}" > $MONGO_ORCHESTRATION_HOME/orchestration.config
  ./.evergreen/run-orchestration.sh
  