Using dplyr::bind_rows() instead of dplyr::rbind_all()

[romainfrancois]

We're tidyverse/dplyr#4579 in the process of releasing dplyr 0.8.4 and this package fail at our reverse dependency checks because the dplyr::rbind_all() function has been formally removed after being deprecated for many versions.

We might revert that decision because it affects a handful of packages, but in any case even if rbind_all() stays a little longer, you still should use bind_rows() instead.

# ggvis

<details>

* Version: 0.4.4
* Source code: https://github.com/cran/ggvis
* URL: http://ggvis.rstudio.com/
* Date/Publication: 2018-09-28 21:50:03 UTC
* Number of recursive dependencies: 53

Run `revdep_details(,"ggvis")` for more info

</details>

## Newly broken

*   checking dependencies in R code ... NOTE
    ```
    Missing or unexported object: ‘dplyr::rbind_all’
    ```