Update Windshaft to 4.7.2

NEWS.md

@@ -5,6 +5,7 @@ Released 2018-mm-dd
 
 New features:
 - CI tests with Ubuntu Xenial + PostgreSQL 10.1 and Ubuntu Precise + PostgreSQL 9.5
+- Upgrades Windshaft to [4.7.2](https://github.com/CartoDB/Windshaft/blob/4.7.2/NEWS.md#version-472). Includes improvements in Mapnik and sets MVT's simplify_distance option to 0.
 
 
 Bug Fixes:

package.json

@@ -48,7 +48,7 @@
     "step-profiler": "~0.3.0",
     "turbo-carto": "0.20.2",
     "underscore": "~1.6.0",
-    "windshaft": "4.7.1",
+    "windshaft": "4.7.2",
     "yargs": "~5.0.0"
   },
   "devDependencies": {