Attempt to fix transition bug

Importing transition relies on side-effects so rollup won't include it by default

package.json

@@ -1,6 +1,6 @@
 {
   "name": "d3-bumps-chart",
-  "version": "0.0.4",
+  "version": "0.0.5",
   "description": "Draw bumps charts.",
   "keywords": [
     "d3",
@@ -21,7 +21,7 @@
     "url": "https://github.com/johnwalley/d3-bumps-chart.git"
   },
   "scripts": {
-    "pretest": "rm -rf build && mkdir build && rollup -c --banner \"$(preamble)\" -f umd -g d3-array:d3,d3-dsv:d3,d3-selection:d3,d3-scale:d3,d3-shape:d3,lodash:_ -n bumpsChart -o build/d3-bumps-chart.js -- index.js",
+    "pretest": "rm -rf build && mkdir build && rollup -c --banner \"$(preamble)\" -f umd -g d3-array:d3,d3-dsv:d3,d3-selection:d3,d3-scale:d3,d3-shape:d3,d3-transition:d3,lodash:_ -n bumpsChart -o build/d3-bumps-chart.js -- index.js",
     "test": "tape 'test/**/*-test.js' && eslint index.js src",
     "prepublish": "npm run test && uglifyjs --preamble \"$(preamble)\" build/d3-bumps-chart.js -c -m -o build/d3-bumps-chart.min.js",
     "postpublish": "zip -j build/d3-bumps-chart.zip -- LICENSE README.md build/d3-bumps-chart.js build/d3-bumps-chart.min.js"
@@ -32,15 +32,15 @@
     "d3-scale": "^1.0.3",
     "d3-selection": "^1.0.2",
     "d3-shape": "^1.0.3",
+    "d3-transition": "^1.0.2",
     "lodash": "^4.15.0"
   },
   "devDependencies": {
-    "babel-preset-es2015-rollup": "^1.2.0",
+    "babel-preset-es2015": "^6.14.0",
     "eslint": "2",
     "package-preamble": "0.0.2",
     "rollup": "0.34",
     "rollup-plugin-babel": "^2.6.1",
-    "rollup-plugin-node-resolve": "^2.0.0",
     "tape": "4",
     "uglify-js": "^2.7.3"
   }

rollup.config.js

@@ -1,5 +1,7 @@
 import babel from 'rollup-plugin-babel';
 
 export default {
-  plugins: [ babel() ],
+  plugins: [ babel({
+      exclude: 'node_modules/**'
+    }) ]
 };

src/.babelrc

@@ -1,3 +1,10 @@
 {
-  "presets": ["es2015-rollup"]
+  "presets": [
+    [
+      "es2015",
+      {
+        "modules": false
+      }
+    ]
+  ]
 }

src/bumpsChart.js

@@ -2,6 +2,7 @@ import {select} from 'd3-selection';
 import {scaleLinear} from 'd3-scale';
 import {line} from 'd3-shape';
 import {max, range} from 'd3-array';
+import 'd3-transition';
 
 const abbrevCamCollege = {
   'A': 'Addenbrooke\'s',