bracket-push: Add new test case
bracket-push: Add new test case

Adds a new test case to cover broken stack-based implementations.

see: https://github.com/exercism/x-common/pull/747

pheanex/xpython,exercism/xpython,exercism/python,exercism/python,jmluy/xpython,smalley/python,jmluy/xpython,exercism/xpython,mweb/python,behrtam/xpython,behrtam/xpython,N-Parsons/exercism-python,pheanex/xpython,mweb/python,N-Parsons/exercism-python,smalley/python