Gem: update Xcodeproj dependency

Gemfile.lock

@@ -18,10 +18,10 @@ GIT
 
 GIT
   remote: https://github.com/CocoaPods/Xcodeproj.git
-  revision: 5510801ca0de8c1dccae739d10a964f6c9180393
+  revision: 37463809b6040e67a53b03d7e5efc65125b297cb
   branch: master
   specs:
-    xcodeproj (0.17.0)
+    xcodeproj (0.18.0)
       CFPropertyList (~> 2.2)
       activesupport (~> 3.0)
       colored (~> 1.2)
@@ -80,7 +80,7 @@ PATH
       json_pure (~> 1.8)
       nap (~> 0.8)
       open4 (~> 1.3)
-      xcodeproj (~> 0.17.0)
+      xcodeproj (~> 0.18.0)
 
 GEM
   remote: http://rubygems.org/

cocoapods.gemspec

@@ -29,7 +29,7 @@ s.files = Dir["lib/**/*.rb"] + %w{ bin/pod bin/sandbox-pod README.md LICENSE CHA
   # Link with the version of CocoaPods-Core
   s.add_runtime_dependency 'cocoapods-core',       "= #{Pod::VERSION}"
   s.add_runtime_dependency 'claide',               '~> 0.6.1'
-  s.add_runtime_dependency 'xcodeproj',            '~> 0.17.0'
+  s.add_runtime_dependency 'xcodeproj',            '~> 0.18.0'
   s.add_runtime_dependency 'cocoapods-downloader', '~> 0.6.1'
   s.add_runtime_dependency 'cocoapods-plugins',    '~> 0.2.0'
   s.add_runtime_dependency 'cocoapods-try',        '~> 0.3.0'