remove mice and tibble as they are not used

Author: jrosen48

DESCRIPTION

@@ -46,7 +46,6 @@ Imports:
     tidyr,
     lme4 (>= 1.1-35.1),
     margins,
-    tibble,
     ggrepel,
     pbkrtest
 Suggests: 
@@ -55,7 +54,6 @@ Suggests:
     forcats,
     knitr,
     rmarkdown,
-    mice,
     roxygen2,
     testthat,
     Matrix (>= 1.6-2)