Fix start url format for paver pa11ycrawler

pavelib/paver_tests/test_paver_bok_choy_cmds.py

@@ -200,7 +200,7 @@ class TestPaverPa11yCrawlerCmd(unittest.TestCase):
             '--pa11y-reporter="1.0-json" '
             '--depth-limit=6 '
         ).format(
-            start_urls=start_urls,
+            start_urls=' '.join(start_urls),
             report_dir=report_dir,
         )
         return expected_statement

pavelib/utils/test/suites/bokchoy_suite.py

@@ -360,7 +360,7 @@ class Pa11yCrawler(BokChoyTestSuite):
             '--pa11y-reporter="{reporter}" '
             '--depth-limit={depth} '
         ).format(
-            start_urls=self.start_urls,
+            start_urls=' '.join(self.start_urls),
             allowed_domains='localhost',
             report_dir=self.pa11y_report_dir,
             reporter="1.0-json",