MapPolyfill dropped from HashMap

[ath0mas]

Even if turf-jsts is ES6, when used in Turf targeting ES5, some syntax breaks its ES5 compatibility
(see Turfjs/turf/issues/1245)

Map
while jsts uses ES6 too, it still imports a polyfill for Map when building HashMap : lines 6-20
turf-jsts recently changed those lines, dropping use of MapPolyfill for a direct call to Map : line 15
change made in 1a9635e between v1.1.0 and v1.1.1 😢

[pbrain19]

:(