Merge pull request #941 from mozilla/greenkeeper-dompurify-0.8.3

Update dompurify to version 0.8.3 🚀

Author: muffinresearch

package.json

@@ -143,7 +143,7 @@
     "camelcase": "3.0.0",
     "classnames": "2.2.5",
     "config": "1.21.0",
-    "dompurify": "0.8.2",
+    "dompurify": "0.8.3",
     "express": "4.14.0",
     "extract-text-webpack-plugin": "1.0.1",
     "helmet": "2.1.2",