Bump html-proofer from 3.19.1 to 3.19.2

Bumps html-proofer from 3.19.1 to 3.19.2.

Commits

• c3c505e 💎 bump to 3.19.2
• d64768a Merge pull request #645 from gjtorikian/why-no-hydra
• 96e691f 2.5 is EOL
• 20f6cf1 Hydra behaves differently
• d13a5b6 Update README.md
• See full diff in compare view