Update integration specs

cocoapods-integration-specs @ b21c0514

-Subproject commit 4bb5eeef8cb713fc2e0abe51f79716d0edceb019
+Subproject commit b21c05141a790ac307a0ff605d2015e58c173889

spec/integration.rb

@@ -279,6 +279,11 @@ describe_cli 'pod' do
                             'install --no-repo-update'
     end
 
+    describe 'Integrates a Pod with a header mappings directory' do
+      behaves_like cli_spec 'install_header_mappings_dir',
+                            'install --no-repo-update'
+    end
+
     describe 'Integrates a Pod using non Objective-C source files' do
       behaves_like cli_spec 'install_non_objective_c_files',
                             'install --no-repo-update'