Update Terraformer

There have been a lot of bug fixes and improvements to both eh core terraformer library and the ArcGIS Parser module has seem a lot of improvements including...

here is a quick summary of the whats new in the ArcGIS Parser...
* will now automatically close rings during conversion https://github.com/Esri/terraformer-arcgis-parser/pull/16
* will strip out invalid rings https://github.com/Esri/terraformer-arcgis-parser/pull/19
* huge performance gains https://github.com/Esri/terraformer-arcgis-parser/pull/4
* harden the parser against edge cases https://github.com/Esri/terraformer-arcgis-parser/issues/6 https://github.com/Esri/terraformer-arcgis-parser/issues/7 https://github.com/Esri/terraformer-arcgis-parser/pull/17