Fix test being broken by localStorage state

Summary:
The test would fail if you changed the angle setting on the calculator.
Now just set it ahead of time instead of testing it.

Test Plan:
* open http://localhost:8000/test/
* see tests pass!
* open http://localhost:8000/exercises/standard_deviation.html
* change the angle mode to RAD
* refresh tests, see them still pass!

Auditors: alex