[gemspec] Update Xcodeproj to `~> 0.23.1`

CHANGELOG.md

@@ -6,6 +6,8 @@ To install release candidates run `[sudo] gem install cocoapods --pre`
 
 ## Master
 
+[Xcodeproj](https://github.com/CocoaPods/Xcodeproj/compare/0.23.0...0.23.1)
+
 ##### Bug Fixes
 
 * Fix the resource script's handling of `.xcasset` files.  

Gemfile.lock

@@ -24,10 +24,10 @@ GIT
 
 GIT
   remote: https://github.com/CocoaPods/Xcodeproj.git
-  revision: fb487113a702e7d85d38d80bbe47076129d0eab7
+  revision: ffc8f9ff6f85fec56aeb48562752951c05e2082d
   branch: master
   specs:
-    xcodeproj (0.23.0)
+    xcodeproj (0.23.1)
       activesupport (>= 3)
       colored (~> 1.2)
 
@@ -78,12 +78,12 @@ PATH
       molinillo (~> 0.2.1)
       nap (~> 0.8)
       open4 (~> 1.3)
-      xcodeproj (~> 0.23.0)
+      xcodeproj (~> 0.23.1)
 
 GEM
   remote: http://rubygems.org/
   specs:
-    activesupport (4.2.0)
+    activesupport (4.2.1)
       i18n (~> 0.7)
       json (~> 1.7, >= 1.7.7)
       minitest (~> 5.1)

cocoapods.gemspec

@@ -29,7 +29,7 @@ Gem::Specification.new do |s|
   # Link with the version of CocoaPods-Core
   s.add_runtime_dependency 'cocoapods-core',       "= #{Pod::VERSION}"
   s.add_runtime_dependency 'claide',               '~> 0.8.1'
-  s.add_runtime_dependency 'xcodeproj',            '~> 0.23.0'
+  s.add_runtime_dependency 'xcodeproj',            '~> 0.23.1'
   s.add_runtime_dependency 'cocoapods-downloader', '~> 0.8.1'
   s.add_runtime_dependency 'cocoapods-plugins',    '~> 0.4.1'
   s.add_runtime_dependency 'cocoapods-try',        '~> 0.4.3'