**What** and **Why**:
* When using npm version 2, `object-assign` and `fbjs` were not getting properly installed
* This PR adds `object-assign` and `fbjs` as explicit dependencies to both `react-test-renderer` and `react-addons`
* Ensure lib/ is packaged for react-test-renderer
* Run npm pack from right working directory
We were running this on the original packages not the compiled ones, resulting in missing files
This copies modules into three separate packages instead of
putting it all in React.
The overlap in shared and between renderers gets duplicated.
This allows the isomorphic package to stay minimal. It can also
be used as a direct dependency without much risk.
This also allow us to ship versions to each renderer independently
and we can ship renderers without updating the main react package
dependency.
