Various fixes & improvements
- ref(crons): Prefer DSN based auth (#1545) by @kamilogorek
- fix(inject): Improve fixup_js_file (#1533) by @loewenheim
- feat(inject): Handle relative and absoule sourcemap URLs (#1530) by @loewenheim
- ref(monitors): Prefer slugs over guids (#1540) by @evanpurkhiser
- feat(auth): Support DSN auth for the API client (#1536) by @evanpurkhiser
- ref(crons): monitors command is not legacy atm (#1538) by @evanpurkhiser
- fix(help): Consistent wording for API keys (#1539) by @evanpurkhiser