Update puma (#3918)

* Update puma

Older versions of puma don't work on newer versions of OSX
puma/puma#2304

I had to bump this gem to get `bundle install` to work

* Update Gemfile

Co-authored-by: Michael Grosser <michael@grosser.it>

Co-authored-by: Michael Grosser <michael@grosser.it>

Gemfile.lock

@@ -474,7 +474,7 @@ GEM
       binding_of_caller (>= 0.7)
       pry (>= 0.9.11)
     public_suffix (4.0.5)
-    puma (4.3.5)
+    puma (4.3.6)
       nio4r (~> 2.0)
     pyu-ruby-sasl (0.0.3.3)
     racc (1.5.2)
@@ -685,7 +685,7 @@ DEPENDENCIES
   pry-rails
   pry-rescue
   pry-stack_explorer
-  puma
+  puma (= 4.3.6)
   rack-mini-profiler
   rails (~> 6.0.3)
   rails-assets-bootstrap-select!