Document how to test a production build

Change-Id: I6a20e0c3978f169d63a8196359376d06b6445dc0

docs/index.rst

@@ -15,6 +15,7 @@ Welcome to Tripleo UI's developer documentation!
    testing
    translation
    packaging
+   production
    contributing
 
 * `Source code`_

docs/production.rst

@@ -0,0 +1,12 @@
+Production
+==========
+
+Building for production
+-----------------------
+
+::
+
+   $ npm run build
+
+This will produce a minified and mangled file in ``dist/tripleo_ui.js``.  It
+also enables React production mode.

docs/testing.rst

@@ -14,6 +14,17 @@ Tests during development
 
 Start Karma to run tests after every change ``npm run test:watch``.
 
+Testing a production build locally
+----------------------------------
+
+::
+
+   $ <kill your webpack-dev-server process>
+   $ npm run build
+   $ cd dist
+   $ python -m SimpleHTTPServer 1111
+   $ <go to http://localhost:1111 in the browser>
+
 Debugging tests
 ---------------