spec: update once-ler

fix a couple issues so we don't have to do weird workarounds when
once-ler'ing certain specs. see:

https://github.com/instructure/once-ler/commit/2259e27
https://github.com/instructure/once-ler/commit/4f21997
https://github.com/instructure/once-ler/commit/8ec55d2

Change-Id: I516e9d2c4c66cabcd3b48460e65878e27bc2d379
Reviewed-on: https://gerrit.instructure.com/37167
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Dave Donahue <ddonahue@instructure.com>
Product-Review: Dave Donahue <ddonahue@instructure.com>
QA-Review: Dave Donahue <ddonahue@instructure.com>