statsExpressions 1.0.0

This is the first stable release of {statsExpressions}!

There is good news and there is bad news that accompanies this milestone.

• The bad news: The API for the package has changed completely: All
  functions return a dataframe, and not an expression, as a default. The
  expression is contained in a list column in the dataframe itself. So, to
  salvage your functions from breaking, you will have to add
  $expression[[1]] to your function calls. For example, if you were using
  the function expr_t_onesample(), you will now have to specify
  expr_t_onesample()$expression[[1]], so on and so forth. But, in general,
  the advice is to not use any of the expr_* functions, which are
  vestigial names for new avatars of these function and will be removed in
  future. The new names are more intuitive, e.g., expr_t_onesample() is now
  called one_sample_test(), etc.

• The good news: There will not be any new changes to any of the current
  functions, except for any change necessary for maintenance or bug squashing.
  Well, to be more precise, this is true only for the functions that have
  "stable" badge.

BUG FIXES

• If the entered dataframe is grouped-tibble, the function internally
  ungroups this (#79).

MINOR CHANGES

• To reduce dependency load, afex has moved from Imports to Suggests.