add descriptive labels to rspec / selenium execution steps
add descriptive labels to rspec / selenium execution steps

[canvas-builds-refspec=ec576a762c98277f90c92de79b8878ddc77cf537]

Change-Id: Ia8e79e5cfcb0409adfbd62a0a6187967597e557c
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/252506
Tested-by: Service Cloud Jenkins <9144042a601061f88f1e1d7a1753ea3e2972119d@instructure.com>
Reviewed-by: Andrea Cirulli <b4e55ef5ee4bae8ad31f7c81009bfc0af1714a1f@instructure.com>
QA-Review: Aaron Ogata <11ccf682c06d1508642f943a3962a1c3d00b8e44@instructure.com>
Product-Review: Aaron Ogata <11ccf682c06d1508642f943a3962a1c3d00b8e44@instructure.com>

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