Setup CI Testing to Test All Feature Combinations

[Carter12s]

A bigger goal would be to eliminate / simplify as many feature combinations as possible.

I think in the long run I'd prefer to break things into more crates, and have users select features by choosing which crates to include. In the meantime we should incorporates something like:

https://github.com/frewsxcv/cargo-all-features

So that checks / tests for feature combinations happen. This will be challenging for our "running_bridge" tests right now, I think I'd like to find a better way to enable / disable those tests.