re-introduce colnames print suggestion in snapshot (closes #797)

Author: simonpcouch

Diff for: tests/testthat/_snaps/translate.md

@@ -2131,6 +2131,7 @@
     Output
       # A tibble: 0 x 3
       # ... with 3 variables: user <chr>, parsnip <chr>, engine <chr>
+      # i Use `colnames()` to see all variable names
 
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