bbbike.psgi: use Plack::Middleware::Rewrite for /

So only / is redirected to bbbike.cgi, and any invalid URL is now
realy a 404.
missing declaration of using_bbbike_test_data
BBBikeApacheSessionCountedHandler is a TODO test on travis
psgi: handle /bbbike URLs correctly
another file for CGI_TEST_FILES
wip: travis: psgi setup