bump sane-topojson requirement to 2.0.0

Author: etpinard

package.json

@@ -85,7 +85,7 @@
     "ndarray-ops": "^1.2.2",
     "right-now": "^1.0.0",
     "robust-orientation": "^1.1.3",
-    "sane-topojson": "^1.2.0",
+    "sane-topojson": "^2.0.0",
     "superscript-text": "^1.0.0",
     "tinycolor2": "^1.3.0",
     "topojson": "^1.6.20",