Tighten up string type representations to prevent illegal values (#214) #876

Job	Run time
build-windows	7m 46s
Build rustls-cert-gen as a standalone package	29s
Validate external types appearing in public API	1m 14s
build (macOS-latest, stable)	1m 5s
build (ubuntu-latest, stable)	5m 31s
Clippy (--all-features)	4m 43s
build (ubuntu-latest, beta)	39s
Measure coverage	41s
build (ubuntu-latest, nightly)	40s
Clippy (--no-default-features --features ring)	4m 41s
Documentation (stable)	45s
build (ubuntu-latest, stable 7 months ago)	50s
Clippy (--no-default-features --features aws_lc_rs)	4m 45s
Documentation (beta)	42s
Clippy (--no-default-features --features aws_lc_rs,pem)	4m 40s
Documentation (nightly)	41s
Documentation (stable 7 months ago)	50s
Format	4s
Check semver compatibility	34s
	41m 20s

Provide feedback