Fix required dev dependencies

jupyterlab/package.json

@@ -15,6 +15,7 @@
     "css-loader": "^0.23.1",
     "extract-text-webpack-plugin": "^1.0.1",
     "file-loader": "^0.8.5",
+    "find-imports": "^0.5.0",
     "json-loader": "^0.5.4",
     "rimraf": "^2.5.0",
     "style-loader": "^0.13.0",

package.json

@@ -28,7 +28,6 @@
     "css-loader": "^0.23.1",
     "expect.js": "^0.3.1",
     "file-loader": "^0.8.5",
-    "find-imports": "^0.5.0",
     "fs-extra": "^0.26.4",
     "istanbul-instrumenter-loader": "^0.1.3",
     "json-loader": "^0.5.4",