Upgrade spring to solve a deprecation warning

Author: ysbaddaden

Gemfile.lock

@@ -555,7 +555,8 @@ GEM
       addressable (>= 2.3.3, < 3.0)
       capybara (>= 2.1, < 3.0)
     slop (3.6.0)
-    spring (1.3.6)
+    spring (2.0.2)
+      activesupport (>= 4.2)
     spring-commands-rspec (1.0.4)
       spring (>= 0.9.1)
     sprockets (2.12.4)

bin/spring

@@ -4,12 +4,14 @@
 # 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)
-    Gem.paths = { "GEM_PATH" => [Bundler.bundle_path.to_s, *Gem.path].uniq }
-    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