Add tests

R/BASiCSParams-methods.R

R/utils.R

tests/testthat/test-BASiCSParams.R

tests/testthat/test-Lun2Params.R

tests/testthat/test-LunParams.R

tests/testthat/test-MFAEstimate.R

tests/testthat/test-MFAParams.R

tests/testthat/test-PhenoParams.R

tests/testthat/test-SCDDParams.R

tests/testthat/test-SCE-functions.R

tests/testthat/test-SimpleParams.R

tests/testthat/test-SplatParams.R

tests/testthat/test-ZINBParams.R

tests/testthat/test-compare.R

tests/testthat/test-listSims.R

tests/testthat/test-lunEstimate.R

tests/testthat/test-phenoEstimate.R

tests/testthat/test-simpleEstimate.R

tests/testthat/test-splat-simulate.R

tests/testthat/test-utils.R