Run-time hardware tests and other changes

[t0mpr1c3]

Compiling with 100% test coverage, but not tested together with the desktop software yet.

To get the tests to run properly, I needed to update travis to Ubuntu focal.

Label: Feature
Milestone 1.0.0
Reference #37

[dl1com]

Wow...that's a really nice piece of work @t0mpr1c3 😮

[t0mpr1c3]

Wow...that's a really nice piece of work @t0mpr1c3 😮

Thanks Chris. We are definitely making some progress. Let's thank @Sturla22 again for setting up the mock framework. I really feel this was such a massive step forward and has really set us up for success.

[t0mpr1c3]

Just to give a bit of an overview on what I am attempting here:

In addition to the feature changes that need implementing, I am pulling apart the structure of the firmware from a hierarchy with everything incorporated into a global Knitter object and moving towards a collection of singleton global classes that interoperate through public interfaces.

There are two goals here:

1. To move further towards a modular structure with standalone elements. This helps uncouple functions from their implementations making changes easier to implement. This would be helpful for example if there are performance concerns regarding position encoding, and we want to recode the interrupt routines in C or assembly. It would be difficult to achieve that using the old structure.

2. Programming to the public interfaces should make mocking more straightforward. It is explicit which methods need to be mocked. Real and mock objects simply become different implementations of the interface.

[t0mpr1c3]

Ready to go.