[RuboCop] Fix offenses

lib/cocoapods/installer.rb

@@ -324,7 +324,7 @@ module Pod
       end
 
       @pod_installers ||= []
-      pod_installer = PodSourceInstaller.new(sandbox, specs_by_platform, can_cache: installation_options.clean?)
+      pod_installer = PodSourceInstaller.new(sandbox, specs_by_platform, :can_cache => installation_options.clean?)
       @pod_installers << pod_installer
       pod_installer
     end

lib/cocoapods/installer/podfile_validator.rb

@@ -16,7 +16,6 @@ module Pod
       #
       attr_reader :warnings
 
-
       # Initialize a new instance
       # @param [Podfile] podfile
       #        The podfile to validate

spec/unit/installer_spec.rb

@@ -402,7 +402,7 @@ module Pod
 
         it 'stores the targets created by the analyzer' do
           @installer.send(:analyze)
-          @installer.aggregate_targets.map(&:name).sort.should == ["Pods-SampleProject", "Pods-SampleProjectTests"]
+          @installer.aggregate_targets.map(&:name).sort.should == ['Pods-SampleProject', 'Pods-SampleProjectTests']
           @installer.pod_targets.map(&:name).sort.should == ['JSONKit']
         end
 
@@ -410,7 +410,7 @@ module Pod
           @installer.update = true
           Installer::Analyzer.any_instance.expects(:update=).with(true)
           @installer.send(:analyze)
-          @installer.aggregate_targets.map(&:name).sort.should == ["Pods-SampleProject", "Pods-SampleProjectTests"]
+          @installer.aggregate_targets.map(&:name).sort.should == ['Pods-SampleProject', 'Pods-SampleProjectTests']
           @installer.pod_targets.map(&:name).sort.should == ['JSONKit']
         end
       end