stricter lint

.jshintrc had errors - it was ignoring 'unused' option
add wunderground API request

use demo key for test, need to apply for real key before deployment
we ask for weather forecast using resort location and then simplify the
response saving only the forecast for the closest period
Refactor lifts to be a plugin
Fix require paths after moving files
Change the place where we keep timestamp
Fix rendering for plugins
extract DB related operations to a separate module