Tests can be run on a device or can be run inside Unity Editor.
It's always a good idea to try setting up tests to run on all
platforms if possible which uncovers platform specific problems.

- EditAndPlayModes
All tests should be put here whenever applicable. They will be run
as EditMode tests when working in Editor and can easily be
converted to PlayMode tests via "Tools > Extenity > Tests" menu.
Also Build Machine can automatically convert them for test builds.

- EditModeOnly
Put the tests here which can only be run in Editor or won't be
meaningful to run on all platforms.

- PlayModeOnly
Put the tests here which requires Unity Play Mode to be run.