and update to prettier 1.19 Also, update `assert()` and remove not null assertions where possibly in `cli`. Closes #3273
This ensures the deno executable is properly created before running the integration tests. Also allows deno_cli to be used as a lib. Docs are now properly generated: https://docs.rs/deno_cli/0.18.4/deno_cli/ Towards #2933 Prep for #2955