next 8.1.1-canary.0

Remove un-needed config from example: #7055
Update AMP example: #7056
Update AMP example to AMP-first wording: 549965282045beda0cf0b31823b35a13014a0d6b
Update dependency to fix with-next-page-transitions example: #7049
Add test for /dashboard/index: #7065
With-apollo example: explicitly pass fetch to HttpLink: #7072
Update fela example: #7051
Disable Terser loader when debugging: #7079
Fix broken link: #7087
Upgrade with-reasonml example to Reason React 0.7 and JSX 3: #7078
Update the recommendation section in examples/with-reasonml: #7089
Run optimizer after validating in dirty AMP mode: #7063
Detect built ins in externals: #7083
Move react-ssr-prepass import inside of: #7095
Export 404 even if undefined in exportPathMap: #6912
Remove dynamic-import-node from the preset: #7096
Update to share HMR and ondemand SSE connection: #7084
Upgrade Terser: #6981

Huge thanks to @ijjk, @Timer, @andy-ob, @koenpunt, @TxHawks, @mottox2, @scull7, @dav-is, @Ephem, and @lfades for helping!