Revert "strip out react propTypes in prod webpack build"

this was doing something funky things in the production
webpack build eg: https://cl.ly/3q130H2z0c0u .
I am going to hold off on enabling this untill we have
a chance to really qa it well

This reverts commit 6e5aef277e.

Change-Id: I2f28b7ccc11208fb2fbc799c99aed2f1e69de241
Reviewed-on: https://gerrit.instructure.com/102569
Tested-by: Jenkins
Reviewed-by: Clay Diffrient <cdiffrient@instructure.com>
Product-Review: Ryan Shaw <ryan@instructure.com>
QA-Review: Ryan Shaw <ryan@instructure.com>

.babelrc

@@ -1,9 +1,4 @@
 {
   "presets": ["es2015", "react", "stage-1"],
-  "plugins": ["add-module-exports"],
-  "env": {
-    "production": {
-      "presets": ["react-optimize"]
-    }
-  }
+  "plugins": ["add-module-exports"]
 }

package.json

@@ -25,7 +25,6 @@
     "babel-polyfill": "6.22.0",
     "babel-preset-es2015": "^6.9.0",
     "babel-preset-react": "^6.11.1",
-    "babel-preset-react-optimize": "^1.0.1",
     "babel-preset-stage-1": "^6.5.0",
     "babel-register": "^6.9.0",
     "coffee-loader": "^0.7.2",