Explicitly depend on react/event-loop

The code has an explicit dependency on React's event-loop component, hence we should explicitly define it as a dependency.

Currently, it's (implicitly) installed as part of a dependency of the clue/socket-react package. IMHO this is an implementation detail that we should not rely on.

Updated dependency graph:
![graph-composer](https://cloud.githubusercontent.com/assets/776829/3275146/370de380-f338-11e3-9861-2ecadfa37418.png)