Offer an `install.sh`-style script for one-liner integration in CI config

[ianfixes]

Offer an `install.sh`-style script for one-liner integration in CI config

[ianfixes]

Now that I've had some time to think about implementing this, I'm not so sure it's a good idea.

The value of the Adafruit install.sh script is that it enables you to compile sketches on CI. With one line of code, you can have the CI machine perform the same steps that you would perform in your development environment: compiling the sketches.

Creating my own install.sh would be fairly trivial, but that would set up a situation where the CI machine has a capability that you don't have on your local machine -- the ability to run unit tests.
This means that the development cycle for unit tests would be:

1. making a change to the codebase
2. committing the change
3. pushing the commit to GitHub
4. waiting for the CI machine to pick up the job
5. waiting for the CI machine to do the initial download of all the Arduino stuff
6. have the CI machine execute unit tests
7. wait for the results to appear, either in the CI console log or a GitHub notification

It seems much more sensible to just download the unit testing capability to your own machine and then just:

1. make a change to the codebase
2. run the unit tests locally (with the same command that the CI machine will use)

Is there a use case I'm not considering here?