PHP 8.0: TraceablePDO adding query arguments (php-debugbar#460)

* php 8 fix

* Update TraceablePDO.php

Update README.md

Add return value to measure() function. (php-debugbar#443)

Change-Id: I0e0277a019545bae6b4a9854b915a83bcea6757a

Co-authored-by: vdauchy <[email protected]>

Skip decimals if < 100ms

Symfony 5 support added (php-debugbar#431)

Update .travis.yml

Fetch support (php-debugbar#422)

Fetch support (php-debugbar#422)

Update JavascriptRenderer.php

RedisStorage performance fix (php-debugbar#357)

Patch increases possible number of records stored and loaded from Redis DB by separating metadata and collector's data and storing them in different hashes.