Add test for Blueprint app-wide url processing
Add test for Blueprint app-wide url processing

The test add coverage for methods: Blueprint.app_url_defaults, and
Blueprint.app_url_preprocessing. This PR increases the coverage of
blueprint module by 2%.

mitsuhiko/flask,fkazimierczak/flask,fkazimierczak/flask,drewja/flask,tristanfisher/flask,pallets/flask,pallets/flask,pallets/flask,drewja/flask,mitsuhiko/flask,tristanfisher/flask,fkazimierczak/flask,drewja/flask