use app_file as the base setting for the App instead of root
use app_file as the base setting for the App instead of root

Sinatra can figure out the values for root, public, and views based on
app_file. Also, the app_file setting can then take a place in the
at_exit hook later.

aldermossy/sequenceserver,IsmailM/sequenceserver,yeban/sequenceserver,IsmailM/sequenceserver,deepakunni3/sequenceserver,aldermossy/sequenceserver,IsmailM/sequenceserver,jasminZ/sequenceserver,vivekiitkgp/sequenceserver,elsiklab/sequenceserver,jasminZ/sequenceserver,yeban/sequenceserver,aldermossy/sequenceserver,vivekiitkgp/sequenceserver,vivekiitkgp/sequenceserver,jasminZ/sequenceserver,deepakunni3/sequenceserver,yeban/sequenceserver,lepbase/lepbase-sequenceserver,lepbase/lepbase-sequenceserver,aldermossy/sequenceserver,elsiklab/sequenceserver,deepakunni3/sequenceserver,lepbase/lepbase-sequenceserver,yeban/sequenceserver,elsiklab/sequenceserver