puma 3.0.2 发布了，与其他Ruby web服务器不同的是，Puma是为速度与并发而生的。Puma是一个为Ruby web程序提供高速处理以及HTTP 1.1并发的服务器小型库。它被设计只用来运行Rack程序
该版本改进内容包括：
* 5 bug fixes:
* Fix 'undefined local variable or method `pid` for #<Puma::ControlCLI:0x007f185fcef968>' when execute pumactl with `--pid` option.
* Fix 'undefined method `windows?` for Puma:Module' when execute pumactl.
* Harden tmp_restart against errors related to the restart file
* Make `plugin :tmp_restart` behavior correct in Windows.
* fix uninitialized constant Puma::ControlCLI::StateFile
* 3 PRs merged:
* Merge pull request #901 from mitto/fix-pumactl-uninitialized-constant-statefile
* Merge pull request #902 from corrupt952/fix_undefined_method_and_variable_when_execute_pumactl
* Merge pull request #905 from Eric-Guo/master