Bump puma from 4.3.5 to 4.3.8

Bumps [puma](https://github.com/puma/puma) from 4.3.5 to 4.3.8.
- [Release notes](https://github.com/puma/puma/releases)
- [Changelog](https://github.com/puma/puma/blob/master/History.md)
- [Commits](puma/puma@v4.3.5...v4.3.8)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Gemfile.lock

@@ -192,7 +192,7 @@ GEM
     multi_test (0.1.2)
     mysql2 (0.5.2)
     nenv (0.3.0)
-    nio4r (2.5.2)
+    nio4r (2.5.7)
     nokogiri (1.10.10)
       mini_portile2 (~> 2.4.0)
     notiffany (0.1.3)
@@ -215,7 +215,7 @@ GEM
     pry-rails (0.3.9)
       pry (>= 0.10.4)
     public_suffix (4.0.1)
-    puma (4.3.5)
+    puma (4.3.8)
       nio4r (~> 2.0)
     rack (2.2.3)
     rack-livereload (0.3.17)