3.21.0
- NEW: Use Fetch instead of XHR when available #1157
- NEW: Ability to specify Custom headers #1166
- NEW: Handle ErrorEvent objects in TraceKit #1162
- BUGFIX: Check for both stacktraces before calling 'isSameException' #1150
- DOCS: Electron integration documentation #1142
- DOCS: Include Sentry Webpack Plugin in the Source Maps documentation #1155