Bump byebug to version 11.1.1

Rails 5.1 updated the `method_source` dependency, which is incompatible
with pry 0.12.x (which some developers are using), and upgrading pry and
pry-byebug requires a more recent version of byebug.

Gemfile

@@ -67,7 +67,7 @@ end
 
 group :development, :test do
   gem "bullet", "~> 5.9.0"
-  gem "byebug", "~> 10.0.0"
+  gem "byebug", "~> 11.1.1"
   gem "factory_bot_rails", "~> 4.8.2"
   gem "faker", "~> 1.8.7"
   gem "i18n-tasks", "~> 0.9.29"

Gemfile.lock

@@ -94,7 +94,7 @@ GEM
     bullet (5.9.0)
       activesupport (>= 3.0.0)
       uniform_notifier (~> 1.11)
-    byebug (10.0.0)
+    byebug (11.1.1)
     cancancan (2.3.0)
     capistrano (3.10.1)
       airbrussh (>= 1.0.0)
@@ -609,7 +609,7 @@ DEPENDENCIES
   audited (~> 4.9.0)
   autoprefixer-rails (~> 8.2.0)
   bullet (~> 5.9.0)
-  byebug (~> 10.0.0)
+  byebug (~> 11.1.1)
   cancancan (~> 2.3.0)
   capistrano (~> 3.10.1)
   capistrano-bundler (~> 1.2)