rebird v1.2.0 released to CRAN

rebird 1.2.0

• Added ebirdsubregionlist() which lists sub-regions within a specified region (thanks @dbradnum, #90).
• Disabled ebirdfreq() (now throws an informative error) as the frequency data request can't be done through the website anymore without logging in first. This request might be added to the eBird API in the near future (#88).
• Added ebirdhotspotlist() which provides a list of hotspots in a region or nearby coordinates (#87).
• Added ebirdregionspecies() which provides a list of species codes seen in a location (thanks @dbradnum, #86).
• Added ebirdchecklistfeed() which provides a list of checklists submitted on a given date at a region or hotspot (thanks @mfoos, #79).