Update puma: 3.11.4 → 3.12.0 (minor)

[depfu[bot]]

We've updated a dependency and here is what you need to know:

name	version specification	old version	new version
puma	~> 3.0	3.11.4	3.12.0

You should probably take a good look at the info here and the test results before merging this pull request, of course.

What changed?

✳️ puma (3.11.4 → 3.12.0) · Repo · Changelog

Commits

See the full diff on Github. The new version differs by 32 commits:

• Merge pull request #1614 from puma/schneems/version-bump
• v3.12.0
• Merge pull request #1611 from jkutner/master
• Update url for binder parsing test for JRuby
• Merge pull request #1604 from puma/schneems/max-thread-metric
• Add max_threads to `Puma.stats`
• Merge pull request #1579 from puma/schneems/waiting
• Merge pull request #1478 from eallison91/dev/ssl_cipher_support
• Add support for --control-url (#1487)
• Fix ssl_v3_rejection test hanging (#1567)
• Bump versions tested on TravisCI (#1566)
• require ruby 2.2+ in gemspec (#1506)
• leak_stack_on_error in test environment (#1557)
• Fix tests
• Include max threads in capacity calculation
• [close #1577] Negative Backpressure Metric
• Merge pull request #1576 from puma/schneems/doc-threadpoo
• Merge pull request #1563 from dannyfallon/df/threadpool-race-fix
• Doc Puma::ThreadPool
• Doc Puma::Runner, Puma::Single, and Puma::Cluster
• Doc Puma::Cluster
• Doc Puma::Client
• Merge pull request #1575 from puma/schneems/reactor-docs
• Document Reactor#add
• Document Reactor#calculate_sleep
• Document initialize arguments
• Update run_internal docs
• Update class docs for Reactor
• Document Puma::Reactor class
• Document Puma::Reactor#run_internal
• Meter accept(2) while taking into account races around thread pool mutex
• Typo

---

Depfu will automatically keep this PR conflict-free, as long as you don't add any commits to this branch yourself. You can also trigger a rebase manually by commenting with @depfu rebase.