Make Webpack a peer dependency to make migration to Webpack 2 easier (c…

…lose #184).

package.json

@@ -60,14 +60,14 @@
     "style-loader": "0.13.1",
     "unified": "~5.0.0",
     "unist-util-visit": "~1.1.0",
-    "webpack": "1.13.2 || ^2.1.0-beta",
     "webpack-dev-middleware": "1.8.1",
     "webpack-hot-middleware": "2.12.2",
     "webpack-merge": "0.14.1"
   },
   "peerDependencies": {
     "react": ">=0.14.0",
-    "react-dom": ">=0.14.0"
+    "react-dom": ">=0.14.0",
+    "webpack": "1 || ^2.1.0-beta"
   },
   "devDependencies": {
     "ava": "~0.16.0",
@@ -89,7 +89,8 @@
     "react-modal": "~1.4.0",
     "sinon": "~1.17.5",
     "unexpected": "~10.16.0",
-    "unexpected-react": "~3.2.3"
+    "unexpected-react": "~3.2.3",
+    "webpack": "1.13.2 || ^2.1.0-beta"
   },
   "scripts": {
     "test": "npm run lint && npm run test:ava",