Fix tooltip positioning

modules/util/tooltip.js

@@ -1,5 +1,6 @@
 import { functor } from './index';
 import * as d3 from 'd3';
+import 'd3-selection-multi';
 export function tooltip() {
 
   var tooltip = function(selection) {
@@ -122,7 +123,7 @@ export function tooltip() {
         break;
     }
 
-    tip.style(pos ?
+    tip.styles(pos ?
       {left: ~~pos.x + 'px', top: ~~pos.y + 'px'} :
       {left: null, top: null});
 

package.json

@@ -24,14 +24,15 @@
   ],
   "license": "ISC",
   "dependencies": {
+    "d3-selection-multi": "1.0.0",
     "diacritics": "1.2.3",
     "lodash": "4.13.1",
     "marked": "0.3.6",
     "osm-auth": "0.2.9",
     "rbush": "2.0.1",
     "sexagesimal": "0.5.0",
-    "wmf-sitematrix": "0.1.2",
-    "togeojson": "0.14.2"
+    "togeojson": "0.14.2",
+    "wmf-sitematrix": "0.1.2"
   },
   "devDependencies": {
     "chai": "~3.5.0",