Enable Spring and bootsnap for faster app load and respone times

Signed-off-by: Sebastian Serth <Sebastian.Serth@student.hpi.de>

bin/rails

@@ -1,4 +1,9 @@
 #!/usr/bin/env ruby
+begin
+  load File.expand_path('../spring', __FILE__)
+rescue LoadError => e
+  raise unless e.message.include?('spring')
+end
 APP_PATH = File.expand_path('../config/application', __dir__)
 require_relative '../config/boot'
 require 'rails/commands'

bin/rake

@@ -1,4 +1,9 @@
 #!/usr/bin/env ruby
+begin
+  load File.expand_path('../spring', __FILE__)
+rescue LoadError => e
+  raise unless e.message.include?('spring')
+end
 require_relative '../config/boot'
 require 'rake'
 Rake.application.run

bin/spring

@@ -1,18 +1,17 @@
 #!/usr/bin/env ruby
 
-# This file loads spring without using Bundler, in order to be fast
-# It gets overwritten when you run the `spring binstub` command
+# This file loads spring without using Bundler, in order to be fast.
+# It gets overwritten when you run the `spring binstub` command.
 
 unless defined?(Spring)
-  require "rubygems"
-  require "bundler"
+  require 'rubygems'
+  require 'bundler'
 
-  if match = Bundler.default_lockfile.read.match(/^GEM$.*?^    spring \((.*?)\)$.*?^$/m)
-    ENV["GEM_PATH"] = ([Bundler.bundle_path.to_s] + Gem.path).join(File::PATH_SEPARATOR)
-    ENV["GEM_HOME"] = ""
-    Gem.paths = ENV
-
-    gem "spring", match[1]
-    require "spring/binstub"
+  lockfile = Bundler::LockfileParser.new(Bundler.default_lockfile.read)
+  spring = lockfile.specs.detect { |spec| spec.name == "spring" }
+  if spring
+    Gem.use_paths Gem.dir, Bundler.bundle_path.to_s, *Gem.path
+    gem 'spring', spring.version
+    require 'spring/binstub'
   end
 end

config/boot.rb

@@ -1,4 +1,4 @@
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
 
 require 'bundler/setup' # Set up gems listed in the Gemfile.
-# require 'bootsnap/setup' # Speed up boot time by caching expensive operations.
+require 'bootsnap/setup' # Speed up boot time by caching expensive operations.