fix: 开放builder-webpack-core版本

Author: LeoEatle

package.json

@@ -30,7 +30,7 @@
     "babel-preset-es2015": "^6.24.1",
     "babel-preset-react": "^6.24.1",
     "babel-preset-stage-0": "^6.24.1",
-    "builder-webpack-core": "0.1.2",
+    "builder-webpack-core": "^0.1.2",
     "caniuse-db": "^1.0.30000764",
     "clean-webpack-plugin": "^0.1.17",
     "css-loader": "^0.28.7",