Speed up Pattern Lab compile times by 3x; speed up Travis

[sghoweri]

Jira

http://vjira2:8080/browse/BDS-2076

Summary

Significantly speeds up Pattern Lab's compile times through a number of performance-related patches.

On Travis:

• Before:
  • Pattern Lab Data compiled in ~12.4s
  • Pattern Lab compiled in ~1m 57.4s
• After:
  • Pattern Lab Data compiles in ~605ms (or ~11.8s faster)
  • Pattern Lab compiles in ~46s (or about 71.4s faster)

Locally (running the php core/console --generate command)

• Before:
  • Pattern Lab compiles in ~33.5s
• After:
  • Pattern Lab compiles in ~12s (no cache) --> about 2x faster!
  • Pattern Lab compiles/recompiles in ~8.8s (with cache) --> more than 3.5x faster!

---

Details

• Patches Pattern Lab PHP to add support for Twig's built-in caching + enables auto_reload by default
• Disables debug mode in Pattern Lab (ie. no more {{ dump() }}) in order to gain significant performance improvements when rendering Twig
• Updates the original Pattern Lab code handling markdown and front-matter parsing with a much faster off the shelf library.
• Updates our Faker.php Twig extension to support PHP 7.4 without breaking PHP 7.3 compatibility
• Blacklists additional files for Pattern Lab to ignore parsing

How to test

• Review changes
• Confirm Pattern Lab compile times have significantly improved when running locally

[danielamorse]

@sghoweri approved with a few inline questions to help me understand the changes.

Locally I found PL compiles in 8-10 secs every time, tested MD files too. Looking forward to these changes!

[sghoweri]

PR was released with v2.21.0