make sure catto_onehot and catto_dummy can return tibbles

[bfgray3]

No description provided.

[bfgray3]

see tidyverse/tibble#85. need to use dplyr::bind_cols instead of cbind.

[bfgray3]

> tt <- as_tibble(matrix(rnorm(100000000), 1000, 1000))
> tt1 <- setNames(tt, paste0("a", seq_along(tt)))
> microbenchmark(as_tibble(cbind(tt, tt1)), bind_cols(tt, tt1), cbind(tt, tt1))
Unit: microseconds
                      expr       min        lq       mean    median         uq       max neval
 as_tibble(cbind(tt, tt1)) 42601.759 43343.209 45215.8420 44681.185 46374.0805 56323.098   100
        bind_cols(tt, tt1)  2005.939  2131.156  2280.5585  2262.736  2377.6900  3424.382   100
            cbind(tt, tt1)   174.894   214.717   258.5104   261.109   294.9795   527.145   100

[bfgray3]

> tt <- matrix(rnorm(100000000), 1000, 1000, dimnames = list(1:1000, paste0("a", 1:1000)))
> ttt <- setNames(as_tibble(tt), paste0("a", colnames(tt)))
> microbenchmark(bind_cols(ttt, as.data.frame(tt)), bind_cols(ttt, as_tibble(tt)), as_tibble(cbind(ttt, tt)))
Unit: milliseconds
                              expr      min       lq     mean   median       uq       max neval
 bind_cols(ttt, as.data.frame(tt)) 19.65335 20.29894 21.33746 20.59145 21.07159  30.03858   100
     bind_cols(ttt, as_tibble(tt)) 23.01287 23.80953 26.87130 24.88373 27.52520 118.07529   100
         as_tibble(cbind(ttt, tt)) 54.55569 58.66774 60.21169 59.58778 60.90112  71.97607   100