v0.2.2

New Features

• Add support for Kenward-Roger adjusted coefficients covariance matrix and
  degrees of freedom in mmrm function call with argument method.
  Options are "Kenward-Roger", "Kenward-Roger-Linear" and "Satterthwaite"
  (which is still the default). Subsequent methods calls
  will respect this initial choice, e.g. vcov(fit) will return the adjusted
  coefficients covariance matrix if a Kenward-Roger method has been used.
• Update the mmrm arguments to allow users more fine-grained control, e.g.
  mmrm(..., start = start, optimizer = c("BFGS", "nlminb")) to set the
  starting values for the variance estimates and to choose the available optimizers.
  These arguments will be passed to the new function mmrm_control.
• Add new argument drop_visit_levels to allow users to keep all levels in visits,
  even when they are not observed in the data. Dropping unobserved levels was done
  silently previously, and now a message will be given. See ?mmrm_control
  for more details.

Bug Fixes

• Previously duplicate time points could be present for a single subject,
  and this could lead to segmentation faults if more than the total number of
  unique time points were available for any subject. Now it is checked that
  there are no duplicate time points per subject, and this is explained also in the
  function documentation and the introduction vignette.
• Previously in mmrm calls, the weights object in the environment where the
  formula is defined was replaced by the weights used internally.
  Now this behavior is removed and your variable
  weights e.g. in the global environment will no longer be replaced.

Miscellaneous

• Deprecated free_cores() in favor of parallelly::availableCores(omit = 1).
• Deprecated optimizer = "automatic" in favor of not specifying the optimizer.
  By default, all remaining optimizers will be tried if the first optimizer fails
  to reach convergence.

Full Changelog: v0.1.5...v0.2.2