Implement a few non-trivial tests

[glwagner]

Currently we've only got

ClimaOceanBiogeochemistry.jl/test/runtests.jl

Line 3 in 0092903

@test 1 == 1

which is of limited utility.

We have a bit of source code so we can add tests for that. #12 also adds some non-trivial docs.

[seamanticscience]

I added some type and reference coefficient tests for the carbon system in #11.

[seamanticscience]

...and now the testing of CarbonAlkalinityNutrients simulation runs successfully too (also in #11).

 Testing Running tests...
 Test Summary: | Pass  Total  Time
 CarbonSolvers |   24     24  7.6s
 Test Summary:                     | Pass  Total  Time
 NutrientsPlanktonBacteriaDetritus |    1      1  0.0s
 [ Info: Initializing simulation...
 [ Info:     ... simulation initialization complete (159.115 ms)
 [ Info: Executing initial time step...
 [ Info:     ... initial time step complete (32.222 seconds).
 [ Info: Simulation is stopping after running for 32.637 seconds.
 [ Info: Model iteration 3 equals or exceeds stop iteration 3.
 Test Summary:             | Pass  Total     Time
 CarbonAlkalinityNutrients |    3      3  1m18.3s
      Testing ClimaOceanBiogeochemistry tests passed 

[navidcy]

there exist some non-trivial tests atm; should we close this?

[seamanticscience]

@hengdiliang @emilyzakem would it be useful to add some checks associated with nutrients_plankton_bacteria_detritus.jl?

[glwagner]

happy to close this