list-ops: updates tests to v2.3.0 (#1454)
list-ops: updates tests to v2.3.0 (#1454)

Resolves #1443
behrtam/xpython,exercism/python,jmluy/xpython,exercism/xpython,smalley/python,smalley/python,N-Parsons/exercism-python,jmluy/xpython,exercism/python,exercism/xpython,N-Parsons/exercism-python,behrtam/xpython