chore: update webpack peerDependency

Author: JackuB

package.json

@@ -12,7 +12,7 @@
     "webpack-core": "^0.6.9"
   },
   "peerDependencies": {
-    "webpack": "^2.0.0"
+    "webpack": "^2.0.0 || ^2.1.0-beta || ^2.2.0-rc"
   },
   "repository": {
     "type": "git",