Update pando-colony frontend to handle repositories updates

[Olivier Sarrouy]

script.js should use an initialization mechanism to fetch all listed repos and add them as external contracts to listen to their UpdateNameAndDescription events and update the application state accordingly.

This could be a good source of inspiration: https://github.com/aragon/aragon-apps/blob/200e6ef0511c01f077e663230fd0d607970702c9/apps/voting/app/src/script.js#L56