Basic CI pipeline

[jrr]

• Configure a basic CI pipeline to run a build on every commit (based on PlatformIO's example)
  • You can see example job output on my fork here
• Correct an #include that was broken on case-sensitive filesystems (like Linux)

Down the road unit tests could run in CI, too, when those exist ;)

Congrats on the Kickstarter success! I'm excited for the project.

[ryanckulp]

thanks @jrr ! tagging Michael from our team to review.