Add bootsnap to development/test bundle and enable it if available

This will enable bootsnap whenver the gem is available.

Gemfile

@@ -323,6 +323,7 @@ group :development do
 end
 
 group :development, :test do
+  gem 'bootsnap', '~> 1.3'
   gem 'bullet', '~> 5.5.0', require: !!ENV['ENABLE_BULLET']
   gem 'pry-byebug', '~> 3.4.1', platform: :mri
   gem 'pry-rails', '~> 0.3.4'

Gemfile.lock

@@ -87,6 +87,8 @@ GEM
     binding_of_caller (0.7.2)
       debug_inspector (>= 0.0.1)
     blankslate (2.1.2.4)
+    bootsnap (1.3.1)
+      msgpack (~> 1.0)
     bootstrap_form (2.7.0)
     brakeman (4.2.1)
     browser (2.2.0)
@@ -500,6 +502,7 @@ GEM
     mini_portile2 (2.3.0)
     minitest (5.7.0)
     mousetrap-rails (1.4.6)
+    msgpack (1.2.4)
     multi_json (1.13.1)
     multi_xml (0.6.0)
     multipart-post (2.0.0)
@@ -986,6 +989,7 @@ DEPENDENCIES
   benchmark-ips (~> 2.3.0)
   better_errors (~> 2.1.0)
   binding_of_caller (~> 0.7.2)
+  bootsnap (~> 1.3)
   bootstrap_form (~> 2.7.0)
   brakeman (~> 4.2)
   browser (~> 2.2)

Gemfile.rails5.lock

@@ -90,6 +90,8 @@ GEM
     binding_of_caller (0.7.2)
       debug_inspector (>= 0.0.1)
     blankslate (2.1.2.4)
+    bootsnap (1.3.1)
+      msgpack (~> 1.0)
     bootstrap_form (2.7.0)
     brakeman (4.2.1)
     browser (2.2.0)
@@ -503,6 +505,7 @@ GEM
     mini_portile2 (2.3.0)
     minitest (5.7.0)
     mousetrap-rails (1.4.6)
+    msgpack (1.2.4)
     multi_json (1.13.1)
     multi_xml (0.6.0)
     multipart-post (2.0.0)
@@ -996,6 +999,7 @@ DEPENDENCIES
   benchmark-ips (~> 2.3.0)
   better_errors (~> 2.1.0)
   binding_of_caller (~> 0.7.2)
+  bootsnap (~> 1.3)
   bootstrap_form (~> 2.7.0)
   brakeman (~> 4.2)
   browser (~> 2.2)

config/boot.rb

@@ -9,3 +9,8 @@ ENV['BUNDLE_GEMFILE'] ||= File.expand_path("../#{gemfile}", __dir__)
 
 # Set up gems listed in the Gemfile.
 require 'bundler/setup' if File.exist?(ENV['BUNDLE_GEMFILE'])
+begin
+  require 'bootsnap/setup'
+rescue LoadError
+  # bootsnap is optional dependency, so if we don't have it it's fine
+end