Split apart spec/selenium/calendar2_spec.rb

Fixes CNVS-16488

Test Plan:
* Make sure jenkins passes

Change-Id: I5be6bea11991955ed1b493e4a202596f542c5352
Reviewed-on: https://gerrit.instructure.com/46279
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Matthew Wheeler <mwheeler@instructure.com>
Product-Review: Matthew Wheeler <mwheeler@instructure.com>
QA-Review: Derek Hansen <dhansen@instructure.com>