v0.15.2 - optimizations for single stream use cases (most people)

What's Changed

• driver/safe test: fix 20% relative tolerance instead of absolute by @jedbrown in #384
• Only doing event recording if multiple streams are created by @coreylowman in #387
• Check ctx::get_current() before calling ctx::set_current() by @coreylowman in #388

New Contributors

• @jedbrown made their first contribution in #384

Full Changelog: v0.15.1...v0.15.2