[Analyzer] Change no-integrate default build configurations to not be empty

lib/cocoapods/installer/analyzer.rb

@@ -196,7 +196,7 @@ module Pod
           else
             target.client_root = config.installation_root
             target.user_target_uuids = []
-            target.user_build_configurations = target_definition.build_configurations || {}
+            target.user_build_configurations = target_definition.build_configurations || { 'Release' => :release, 'Debug' => :debug }
             if target_definition.platform.name == :osx
               target.archs = '$(ARCHS_STANDARD_64_BIT)'
             end

spec/unit/installer/analyzer_spec.rb

@@ -104,7 +104,7 @@ module Pod
 
         target.client_root.should == config.installation_root
         target.user_target_uuids.should == []
-        target.user_build_configurations.should == {}
+        target.user_build_configurations.should == { 'Release' => :release, 'Debug' => :debug }
         target.platform.to_s.should == 'iOS 6.0'
       end