* Fixes#929
* Updated `ci.yml` to define `GITHUB_CI`
* Compilation will now error if VSELECT is enabled on hardware versions that don't support it (any version other than HW5).
* HW4 and SERIAL might work but are untested. The error message for these versions reflects this.
* Erroring when unsafe configurations are defined can be overridden by defining `ALLOW_UNSAFE_CONFIG` which will throw a warning instead.
* This should only be done if trying to implement or test on a currently unsupported platform.
* If both `GITHUB_CI` and `ALLOW_UNSAFE_CONFIG` are defined an error will be thrown causing the CI tests to fail. This is just in case someone makes a commit with it defined.