Run the test suite with the Numba Linker

[brandonwillard]

To move forward with the Numba backend (e.g. as the default/C replacement), we need to run our tests with the default mode changed to Numba.

Some tests will force the use of certain backends, but those tests should always be specific to said backends—or functionality that directly interacts/depends on them—so the majority of tests should end up using the default backend, or at least the Linker associated with the FAST_RUN and FAST_COMPILE modes.

Regardless, we need to do this and start addressing the failures we observe. When we get all the tests working under Numba, and finish #423, we can start taking steps to replace/remove the C backend completely.

NB: Some Types haven't been implemented in Numba (e.g. RandomStateTypes), so we should expect those to fail until we've added support.