Webpack config prod/dev split

EDUCATOR-1448

Modifies paver webpack task to use production configuration in all
non-devstack environments, and a development config in devstack.

package.json

@@ -13,9 +13,9 @@
     "coffee-loader": "^0.7.3",
     "coffee-script": "1.6.1",
     "css-loader": "^0.28.5",
-    "@edx/edx-bootstrap": "0.3.4",
-    "@edx/paragon": "0.1.0",
-    "@edx/studio-frontend": "0.2.0",
+    "@edx/edx-bootstrap": "^0.4.0",
+    "@edx/paragon": "^0.2.0",
+    "@edx/studio-frontend": "^0.3.0",
     "edx-pattern-library": "0.18.1",
     "edx-ui-toolkit": "1.5.2",
     "exports-loader": "^0.6.4",
@@ -45,6 +45,7 @@
     "underscore": "~1.8.3",
     "underscore.string": "~3.3.4",
     "webpack": "^2.2.1",
+    "webpack-merge": "^4.1.0",
     "webpack-bundle-tracker": "^0.2.0",
     "which-country": "1.0.0"
   },