Hotfix release checklist (pool 0.1.2)

[bborgesr]

Code completion (this PR)

• Fix all dbplyr wrapper functions (i.e. change ... = ... to ...)
• Fix positioning of stop("Maximum number of objects in pool has been reached") (currently throwing errors when it shouldn't)
• Add tests for both fixes above to prevent future regression
• Add more small executable example in the Rd-files
• Rebase and use difftime everywhere, per #48 (also, include NEWS item with credit to @caewok)
• Remove \dontrun in the Rd-files
• Close all obsolete issues
• dbplyr:
  • Make sure all relevantdbplyr functions are wrapped in pool (including the deprecated ones, see tidyverse/dbplyr#40 (comment)). Edit: as of today (25/10/2017), there's no .DBIConnection methods declared in either dplyr or dbplyr that are not also wrapped in pool.
  • Request an article about DBI vs dplyr - when to use one vs the other (rstudio/db.rstudio.com#41)

Release checklist (new PR, no code changes there)

• Create a new branch for the release, like v0.1.2-rc
• Run devtoools::check() and address any possible problems
• Bump version to 0.1.2 in NEWS and DESCRIPTION
• Commit and push to github
• Download “clean” copy of package and build source package
• Upload to CRAN
• When accepted to CRAN:
  • create an annotated tag for the "version bump” commit

  git tag -a v0.1.2 -m "pool 0.1.2 on CRAN"
  git push --tags

  • create and normal-merge a PR for the new release branch

Writing

• Draft blog post
• Merge blog post: https://github.com/rstudio/blog/pull/57
• Update articles in shiny-dev-center
  • Make sure to include all relevant info from original README and original articles
  • Incorporate @slopp's feedback:
    • use case for creating a pool inside the server function (and scoping in general)
    • Rmd documents and how to connect to a database from within one
    • scaling across R projects