2.16.0

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