[Xcodeproj] Adapt for interface change.

lib/cocoapods/installer/user_project_integrator/target_integrator.rb

@@ -129,7 +129,7 @@ module Pod
           frameworks = user_project.frameworks_group
           native_targets.each do |native_target|
             library = frameworks.files.select { |f| f.path == target.product_name }.first ||
-                      frameworks.new_static_library(target.name)
+                      frameworks.new_product_ref_for_target(target.name, :static_library)
             unless native_target.frameworks_build_phase.files_references.include?(library)
                    native_target.frameworks_build_phase.add_file_reference(library)
             end

spec/unit/installer/user_project_integrator/target_integrator_spec.rb

@@ -29,7 +29,7 @@ module Pod
       end
 
       it 'returns the targets that need to be integrated' do
-        pods_library = @sample_project.frameworks_group.new_static_library('Pods')
+        pods_library = @sample_project.frameworks_group.new_product_ref_for_target('Pods', :static_library)
         @target.frameworks_build_phase.add_file_reference(pods_library)
         @target_integrator.stubs(:user_project).returns(@sample_project)
         @target_integrator.native_targets.map(&:name).should.be.empty?