[TargetInspector] Quote each enumerated link_with target separately

lib/cocoapods/installer/analyzer/target_inspector.rb

@@ -96,7 +96,8 @@ module Pod
           native_targets = user_project.native_targets
           if link_with = target_definition.link_with
             targets = native_targets.select { |t| link_with.include?(t.name) }
-            raise Informative, "Unable to find the targets named `#{link_with.to_sentence}` to link with target definition `#{target_definition.name}`" if targets.empty?
+            raise Informative, "Unable to find the targets named #{link_with.map { |x| "`#{x}`" }.to_sentence}" \
+              "to link with target definition `#{target_definition.name}`" if targets.empty?
           elsif target_definition.link_with_first_target?
             targets = [native_targets.first].compact
             raise Informative, 'Unable to find a target' if targets.empty?

spec/unit/installer/analyzer/target_inspector_spec.rb

@@ -71,12 +71,12 @@ module Pod
 
       it 'raises if it is unable to find the targets specified by the target definition' do
         target_definition = Podfile::TargetDefinition.new(:default, nil)
-        target_definition.link_with = ['UserTarget']
+        target_definition.link_with = %w(UserTarget AnotherUserTarget)
         user_project = Xcodeproj::Project.new('path')
 
         target_inspector = TargetInspector.new(target_definition, config.installation_root)
         e = lambda { target_inspector.send(:compute_targets, user_project) }.should.raise Informative
-        e.message.should.match /Unable to find the targets/
+        e.message.should.match /Unable to find the targets named `UserTarget` and `AnotherUserTarget`/
       end
 
       it 'returns the target with the same name of the target definition' do