5.20.1

• [react] feat: Add instrumentation for React Router v3 (#2759)
• [apm/tracing] fix: Make sure fetch requests are being timed correctly (#2772)
• [apm/tracing] fix: Make sure pageload transactions start timestamps are correctly generated (#2773)
• [react] ref: Use inline types to avoid redux dependency. (#2768)
• [core] ref: Expose sentry request for electron (#2774)
• [node] fix: Set transaction on scope in node for request (#2769)
• [browser] fix: Make sure that DSN is always passed to report dialog (#2770)