Add tracing example, `strict` feature, more tests... #52

Job	Run time
Lint	1m 54s
Test Rust source (stable, ubuntu-latest)	9s
Test Rust source (stable, ubuntu-latest, tracing)	17s
Test Rust source (stable, ubuntu-latest, strict)	27s
Test Rust source (stable, ubuntu-latest, tracing, strict)	5s
Test Rust source (stable, windows-latest)	52s
Test Rust source (stable, windows-latest, tracing)	1m 8s
Test Rust source (stable, windows-latest, strict)	1m 3s
Test Rust source (stable, windows-latest, tracing, strict)	15s
Test Rust source (stable, macos-latest)	17s
Test Rust source (stable, macos-latest, tracing)	20s
Test Rust source (stable, macos-latest, strict)	18s
Test Rust source (stable, macos-latest, tracing, strict)	9s
Test Rust source (nightly, ubuntu-latest)	23s
Test Rust source (nightly, ubuntu-latest, tracing)	9s
Test Rust source (nightly, ubuntu-latest, strict)	17s
Test Rust source (nightly, ubuntu-latest, tracing, strict)	5s
Test Rust source (nightly, windows-latest)	3m 35s
Test Rust source (nightly, windows-latest, tracing)	1m 50s
Test Rust source (nightly, windows-latest, strict)	1m 19s
Test Rust source (nightly, windows-latest, tracing, strict)	41s
Test Rust source (nightly, macos-latest)	15s
Test Rust source (nightly, macos-latest, tracing)	22s
Test Rust source (nightly, macos-latest, strict)	14s
Test Rust source (nightly, macos-latest, tracing, strict)	7s
Test crate release	0s
Release crate	0s
	16m 31s

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