bump puffing-billy

Gemfile

@@ -226,7 +226,7 @@ group :test do
   gem 'webmock', '~> 3.8.2', require: false
 
   # Mock selenium requests through proxy (for feature tests)
-  gem 'puffing-billy', '~> 2.3.1'
+  gem 'puffing-billy', '~> 2.4.0'
   gem 'table_print', '~> 1.5.6'
 
   gem 'equivalent-xml', '~> 0.6'

Gemfile.lock

@@ -708,7 +708,7 @@ GEM
       binding_of_caller (~> 0.7)
       pry (~> 0.13)
     public_suffix (4.0.5)
-    puffing-billy (2.3.1)
+    puffing-billy (2.4.0)
       addressable (~> 2.5)
       em-http-request (~> 1.1, >= 1.1.0)
       em-synchrony
@@ -1083,7 +1083,7 @@ DEPENDENCIES
   pry-rails (~> 0.3.6)
   pry-rescue (~> 1.5.2)
   pry-stack_explorer (~> 0.5.1)
-  puffing-billy (~> 2.3.1)
+  puffing-billy (~> 2.4.0)
   puma (~> 4.3.5)
   rack-attack (~> 6.3.1)
   rack-cors (~> 1.1.1)