tidytext 0.3.0

• Use vdiffr conditionally
• Bug fix/breaking change for collapse argument to unnest_functions(). This argument now takes either NULL (do not collapse text across rows for tokenizing) or a character vector of variables (use said variables to collapse text across rows for tokenizing). This fixes a long-standing bug and provides more consistent behavior, but does change results for many situations (such as n-gram tokenization).