limit "responders" gem to version ~> 2.4.1

Gemfile

@@ -13,6 +13,10 @@ gem 'puma', '~> 3.11'
 
 gem 'devise', '~> 4.4'
 gem 'devise-i18n', '~> 1.6'
+
+# responders 3 depends on Ruy >= 2.4.0, let's keep a 2.x for now
+gem 'responders', '~> 2.4.1' 
+
 gem 'simple_form', '~> 4.0'
 gem 'pundit', '~> 1.1'
 

Gemfile.lock

@@ -253,9 +253,9 @@ GEM
     rbnacl (4.0.2)
       ffi
     regexp_parser (1.6.0)
-    responders (3.0.0)
-      actionpack (>= 5.0)
-      railties (>= 5.0)
+    responders (2.4.1)
+      actionpack (>= 4.2.0, < 6.0)
+      railties (>= 4.2.0, < 6.0)
     rubocop (0.56.0)
       parallel (~> 1.10)
       parser (>= 2.5)
@@ -378,6 +378,7 @@ DEPENDENCIES
   rails (~> 5.2.0)
   rails-i18n (~> 5.1)
   rbnacl (>= 3.2, < 5.0)
+  responders (~> 2.4.1)
   rubocop (~> 0.56.0)
   sass-rails (~> 5.0)
   selenium-webdriver