[Init] Only create target definitions for native targets

lib/cocoapods/command/init.rb

@@ -62,7 +62,7 @@ module Pod
           # use_frameworks!
         PLATFORM
 
-        project.targets.each do |target|
+        project.native_targets.each do |target|
           podfile << target_module(target)
         end
         podfile << "\n"

spec/functional/command/init_spec.rb

@@ -53,15 +53,17 @@ module Pod
         project.new_target(:application, 'AppA', :ios)
         project.new_target(:application, 'AppB', :ios)
         project.new_target(:application, "App'C", :ios)
+        project.new_aggregate_target('Aggregate')
         project.save
 
         run_command('init')
 
-        config.podfile.nil?.should == false
-        config.podfile.target_definitions.length.should == project.targets.length + 1
-        config.podfile.target_definitions['AppA'].nil?.should == false
-        config.podfile.target_definitions['AppB'].nil?.should == false
-        config.podfile.target_definitions["App'C"].nil?.should == false
+        config.podfile.should.not.be.nil
+        config.podfile.target_definitions.length.should == project.targets.length
+        config.podfile.target_definitions['AppA'].should.not.be.nil
+        config.podfile.target_definitions['AppB'].should.not.be.nil
+        config.podfile.target_definitions["App'C"].should.not.be.nil
+        config.podfile.target_definitions['Aggregate'].should.be.nil
       end
     end