Restore SpecFlow or other Integration Tests to Habitat Project Module

[nickwesselman]

Is your feature request related to a problem? Please describe.
SpecFlow tests were removed at some point during the SC9 upgrade development:
https://github.com/Sitecore/Habitat/tree/v1.5/src/Project/Habitat/specs

We should consider whether it makes sense to restore / maintain these.

Describe the solution you'd like
Working example of integration tests in the Project layer.
http://helix.sitecore.net/devops/testing/integration-testing.html

Describe alternatives you've considered
We could leave them out, considering everyone is going to use a different tool, and there's not a whole lot that's Sitecore-specific to these.

Additional context
Need to consider desire to simplify Habitat and evolve it, might not make sense to put the effort into this yet.