Bug - Fix tidy_multi_single_dist() Fails on distribution with single parameter

[spsanderson]

No description provided.

[spsanderson]

  # Get column names from the param_grid in order to make the dist_type column ----
  cols <- names(param_grid %>% dplyr::select(-c(.n, .num_sims)))
  
  if (length(cols) == 1){
    dff$dist_name <- paste0(dist_type, " c(", dff[, cols], ")")
  } else {
    dff$dist_name <- paste0(
      paste0(dist_type, " c("),
      apply(dff[, cols], 1, paste0, collapse = ", "),
      ")"
    )
  }