zippeR v0.1.1

From NEWS.md

• Updates to README.md and NEWS.md to reflect the fact that the package is now on CRAN
• Resolve R CMD check issue where examples in zi_crosswalk and zi_load_crosswalk fail on CI because a HUD key is not available to them
• Fail informatively if tigris is not working due to U.S. Census Bureau servers being unavailable. At this time TigerWeb is not used as a backup due to the limited availability of ZCTA data

What's Changed

• Documentation by @chris-prener in #2
• fix reference entries by @chris-prener in #3
• Cran patch by @chris-prener in #4

Full Changelog: v0.1.0...v0.1.1