jenk bins quantification method
fixed tests
fixed sidedness of default
jenks now immutable
init 2 more methods
added Quantile and Heads/Tails bin methods
better min/max init for class map
added the requested makepoint simplification
added jenks doc
added quantile doc
added Heads/Tails doc
added doc for latlng
added test coverage for bin methods
added quantification methods
added quantification methods to bubble map
added iterations ot jenks search
Merge branch 'quantification_methods' of github.com:CartoDB/cartodb20 into quantification_methods
adding iteration support
added news.md update
added float8 support to cdb_latlng
Merge branch 'quantification_methods' into develop