Added coverage for duplicate states in HierarchicalMachine

[thedrow]

Coverage for these conditions were missing so I added them 😃.

[coveralls]

Coverage increased (+0.09%) to 98.612% when pulling 4ed2e3c on thedrow:increase-coverage into 070b450 on pytransitions:master.

[aleneum]

Nice! Could you add those tests to test_enum.py instead (in particular here)? This will make sure that users of Python 2.7 without the enum34 module can run the tests as well (since enum tests will be skipped).

I see that Travis' Python 2.7 job is not failing suprisingly. More surprisingly, the tests are actually executed instead of skipped. Maybe enum34 is installed by default since it is no dependency of transitions. When I run tests locally, test_enum will be skipped for Python 2.7.

[thedrow]

I was about to do the changes you requested today.
Do I need to do them anyway or are you going to do so?