v1.2.1

Maintenance release completing the USGS official software release
review (#72). No package code changed.

• Cleaned up vignette messages noted in review (#96).
• Web service walkthroughs are now website-only articles at
  https://doi-usgs.github.io/hydroloom/; hydroloom.Rmd is the only
  installed vignette.
• Citation updated to the software release DOI,
  https://doi.org/10.5066/P16RS3UZ.

hydroloom_1.2.1.tar.gz