spec: once-ler, now with sharding support

revisit some already once-ler'd specs, reduce runtime of modified files
by ~20% (5:20 -> 4:10 locally)

Change-Id: I60ee5cb1cd1491d8c3c9acc2a7d990303529cb96
Reviewed-on: https://gerrit.instructure.com/37607
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Cody Cutrer <cody@instructure.com>
Product-Review: Jon Jensen <jon@instructure.com>
QA-Review: Jon Jensen <jon@instructure.com>