Promote some step events to INFO

Summary:
Fixes https://github.com/dagster-io/dagster/issues/1666 by ensuring some structured logs are
printed to the console on a naive hello-world invocation

Test Plan: Unit, manual

Reviewers: #ft, schrockn

Reviewed By: #ft, schrockn

Subscribers: alangenfeld

Differential Revision: https://dagster.phacility.com/D815