insight 1.5.2

Changes

• Major performance improvement for compact_list on very large, nested list
  objects.

• get_varcov() now explicitly works for lavaan objects.

Bug fixes

• get_modelmatrix() now correctly handles brms models fitted with
  0 + Intercept formulas.

• get_priors() did not return degrees of freedom for Student's t-distribution
  for rstanarm models.

• Fixed issue in get_variance() for brms intercept-only models.