Purge cache when server is started

Given the server can yield empty results before initial sync is
completed it makes sense to purge the cache after the results have been
received. That way the cache results should remain correct.
Allow GitHub token to be used

This helps with the rate limits.
Merge branch 'master' into sync

Conflicts:
	config/config.template.js
	lib/scrape_bootstrap.js
	lib/scrape_jquery.js
	package.json
	serve.js