Enhance tests.test_cli.test_find_best_app (#1882)
Enhance tests.test_cli.test_find_best_app (#1882)

This commit adds a test case for `test_find_best_app` where
Module object does not contain Flask application.
Also cleans the function little bit to provides more meaningful comment.
tristanfisher/flask,drewja/flask,fkazimierczak/flask,fkazimierczak/flask,Endika/flask,adrianmoisey/cptdevops,tristanfisher/flask,drewja/flask,mitsuhiko/flask,pallets/flask,pallets/flask,auready/flask,Endika/flask,dawran6/flask,mitsuhiko/flask,fkazimierczak/flask,auready/flask,drewja/flask,adrianmoisey/cptdevops,dawran6/flask,pallets/flask