Add eg and possibly support for date based searches

[sckott]

see source of page http://stingersplace.com/js/BISON/speciesByDecade.html to see examples of doing range based query

e.g.

https://bison.usgs.gov/solr/occurrences/select/?q=ITISscientificName%3A%22Bison%20bison%22&rows=10&facet=true&facet.query=year:[*%20TO%201800]&facet.query=year:[1801%20TO%201810]&facet.query=year:[1811%20TO%201820]&facet.query=year:[1821%20TO%201830]&facet.query=year:[1831%20TO%201840]&facet.query=year:[1841%20TO%201850]&facet.query=year:[1851%20TO%201860]&facet.query=year:[1861%20TO%201870]&facet.query=year:[1871%20TO%201880]&facet.query=year:[1881%20TO%201890]&facet.query=year:[1891%20TO%201900]&facet.query=year:[1901%20TO%201910]&facet.query=year:[1911%20TO%201920]&facet.query=year:[1921%20TO%201930]&facet.query=year:[1931%20TO%201940]&facet.query=year:[1941%20TO%201950]&facet.query=year:[1951%20TO%201960]&facet.query=year:[1961%20TO%201970]&facet.query=year:[1971%20TO%201980]&facet.query=year:[1981%20TO%201990]&facet.query=year:[1991%20TO%202000]&facet.query=year:[2001%20TO%202010]&facet.query=year:[2011%20TO%20*]&wt=json

[sckott]

• bison: rbison::bison_solr(eventDate = c('2018-03-01', '2018-03-29'))
• gbif: rgbif::occ_data(eventDate = '2018-03-01,2018-03-29')
• ecoengine: ee_observations2(min_date="1980-01-01", max_date="2018-01-01")
• antweb: aw_data2(min_date="2011-01-01", max_date="2011-06-01")
• inat: spocc_inat_obs(date_start = '2015-01-01', date_end = '2015-12-31')
• ebird: NOT POSSIBLE
• vernet: rvertnet::searchbyterm(year = c('>=1900', '<=1940'), month = c(">=1", "<=5"), day = c(">=1", "<=5"))
• idigbio: idigbioopts = list(rq = list(type = "range", gte = "1980-01-01", lte = "1982-01-01"))
• obis: obis_search('Mola mola', startdate = "2015-01-01", enddate = "2018-03-01")
• ala: ala_search(eventDate = c('2018-03-01', '2018-03-29'))