v9.1.5-canary.6

Patches

• Update CI/test set up: #9499
• Purge Babel Cache: #9514
• Remove Legacy Code: #9515
• Remove Broken Example (with-apollo-auth): #9516
• Fix AMP HTML content emit: #9468
• Catch Telemetry Initialization Error: #9518
• Update progressive enhancement example: #9507
• CSS Support Customization: #9502
• Specify Invalid Dynamic Route Values: #9525

Credits

Huge thanks to @ijjk and @maapteh for helping!