Some updates to the Drill R interface (the "sergeant" package) to start the new year

[Bob Rudis <bo...@rud.is>]

HNY Drillers!

I've dropped a couple of posts on the R sergeant package enhancements as a result of the epic 1.15.0 release (it was a great present for the holidays!).

This:

   https://rud.is/b/2019/01/09/on-the-road-to-0-8-0-some-additional-new-features-coming-in-the-sergeant-package/

covers some more cosmetic enhancements but also details the fact that the package now takes advantage of the super amazingly cool addition of metadata that Charles added to the REST API JSON result sets.

This:

   https://rud.is/b/2019/01/02/apache-drill-1-15-0-sergeant-0-8-0-pcapng-support-proper-column-types-mounds-of-new-metadata/

talks about 2 things:

- I wrapped up the Docker dance so that doing something like
  `drill_up(data_dir = "~/Data")` in R will pull (if not local
  already) the latest image and, launch the container, then
  it maps the value of  `data_dir` into `/data` mount point
  in the container and also setup a `dfs.d` workspace tied to
  that new mapping so folks don't have to add workspaces
  manually (or programmatically) after the fact.

- Delimited files (e.g. CSV/CSVH) generally require the use
  of CTAS to get something useful going so there's now a new
  function that will generate a CTAS statement from a query.
  There's a complete example in the post so I won't waste
  email bytes on it here.

If there are any sergeant users that have other features they'd like in the package don't ever hesitate to drop an issue on sr.ht, GitLab or GitHub.

-Bob