Changed app.js

[beheradibas]

It is till not behaving properly , though it should have been able to identify winning positions but it is not finding those, thus further changes are required.

[beheradibas]

The modification needs to be done on heuristic values,
as we are taking five moves forward , there exist a solution where 3 AI pieces are stacked over one another and that is getting more priviledge than the ones blocking.