[autotest] Loosens board list check when adding new board labels.

testbed may have a mix of different boards. This change loosens the board list
check to allow any board labels ending with -number to be added to a host.

BUG=chromium:660271
TEST=unittest

Change-Id: If5f8487472f1092b5ebc24e3df90c7965aa382d0
Reviewed-on: https://chromium-review.googlesource.com/407068
Commit-Ready: Dan Shi <dshi@google.com>
Tested-by: Dan Shi <dshi@google.com>
Reviewed-by: Dan Shi <dshi@google.com>
diff --git a/server/site_utils_unittest.py b/server/site_utils_unittest.py
index a44e90d..6d7edf8 100644
--- a/server/site_utils_unittest.py
+++ b/server/site_utils_unittest.py
@@ -52,5 +52,19 @@
                              '%s' % (test_job_name, expected_info))
 
 
+    def test_board_labels_allowed(self):
+        """Test method board_labels_allowed."""
+        boards = ['board:name']
+        self.assertEquals(True, site_utils.board_labels_allowed(boards))
+        boards = ['board:name', 'board:another']
+        self.assertEquals(False, site_utils.board_labels_allowed(boards))
+        boards = ['board:name-1', 'board:name-2']
+        self.assertEquals(True, site_utils.board_labels_allowed(boards))
+        boards = ['board:name-1', 'board:another-2']
+        self.assertEquals(True, site_utils.board_labels_allowed(boards))
+        boards = ['board:name', 'board:another-1']
+        self.assertEquals(False, site_utils.board_labels_allowed(boards))
+
+
 if __name__ == '__main__':
     unittest.main()