Tests for survival models

[hfrick]

This tests the error message for trying to use proportional_hazards() with the glmnet engine without a penalty value because that's the thing the translate() method for PH models does in addition to the default translate() method.

The rest of the tests for proportional_hazards() and survival_reg() is more of a placeholder because parsnip does not have any engines for these models. The actual tests on primary and engine args for those models are in censored, see https://github.com/tidymodels/censored/pull/208.