This change aims to streamline the integrationtest suite and reduce friction when running (parts of) test suites.
Changes:
- add `test-testname` to makefile to easily run one suite
- made skipping tests first class citizen in test.sh (all available testsuites and the reasons they are skipped are now better exposed and discovered)
- suppress some output of gotest unless there is an error
- no longer build binary for examples and gotest suites
- removed .SILENT from makefile as it being applied to only some targets makes it feel weird (I just learned about this option btw, feel free to comment on this change)
- move individual tests out of `test.sh` and into `test-misc.sh`
- introduced the concept of testsuites to `test.sh`
- New docker command for quickly running tasks in a Linux environment.
- Updated docs with macOS specific details.
- Fixed some test issues.
- Add (fallible) macOS test target for Travis.
It probably needs environment changes and other differences to be more
effective, but if anything it adds a placeholder for improvement, and
shows some solidarity with the reproducible builds project that was
started in debian.
