For backward compat, build-tools package isn't added to FloatingPanel
project file as a local package. Because it breaks builds on Xcode 14.2
or earlier according to the swift version.
I confirmed this behavior was improved on Xcode 15 beta.
But so far we need to add the build-tools package into the project
file manually as a local package to work the build tool plugin.
* Updated 'ci' workflow for Xcode 13.3.1
* Modernized and simplified the workflow using 'strategy.matrix'
* 'arm64-apple-ios15.4' target is not included in swiftpm because its build gets an build error.
Because of the migration from travis-ci.org to travis-ci.com. As a
bonus, ci builds on github actions are much faster.
This repo still needs travis-ci for testing on iOS 10/11/12 simulators
on Xcode11.x. So this doesn't remove .travis.yml
Shin Yamamoto