* Bump XcodeProj and Spectre
* Add LinuxMain.swift
* Linux test fixups
* Add CI job for ubuntu-latest
* Use URLs in glob logic to avoid Linux/Mac foundation inconsistencies
* fatalError when --enable-test-discovery is not used
* Update fixtures
They changed because of a bugfix in XcodeProj: https://github.com/tuist/XcodeProj/pull/563
* Update CHANGELOG.md