Internal improvements; drop <go1.13

• Rewrote the github actions. Enforce much more strict lints, including gosec.
• Bumped minimal support to go1.13 and removed support code for older code.
• Skip change detector test cases that were broken on 386, arm, arm64, mipsle, mips64le, ppc64le, riscv64 and s390x. Thanks @anthonyfok!

Full Changelog: v2.2.2...v2.3.0