Refactor and reset the time in the setUp of the calendar test

This is mainly to address Issue #844 which caused the running of this test to influence all tests that use external https sources (so Persona, email, etc).

While I was there I got rid of the faux teardown (which is cleared when indexeddb is cleared out).

`v1.0.1` -> Tested ok
`v1-train` -> Tested OK
`desktop` -> Untested