fix setbranch command for python3

Author: LD250

jenkins_cli/cli.py

@@ -192,7 +192,7 @@ def setbranch(self, args):
         scm_name, branch_node = self._get_scm_name_and_node(root)
         if branch_node is not None:
             branch_node.text = args.branch_name
-            new_xml = ElementTree.tostring(root)
+            new_xml = ElementTree.tostring(root, encoding='unicode')
             self.jenkins.reconfig_job(job_name, new_xml)
             print('Done')
         else:

tests/test_cli.py

@@ -228,7 +228,7 @@ def test_info(self, patched_get_job_name, patched_get_job_info, patched_get_job_
     @mock.patch.object(jenkins.Jenkins, 'reconfig_job')
     @mock.patch.object(jenkins.Jenkins, 'get_job_config')
     @mock.patch.object(jenkins.Jenkins, 'get_job_name', return_value='Job1')
-    def test_set_branch(self, patched_get_job_name, patched_get_job_config, patched_reconfig_job):
+    def test_setbranch(self, patched_get_job_name, patched_get_job_config, patched_reconfig_job):
         patched_get_job_config.return_value = EMPTY_SCM_XML
         self.args.job_name = 'Job1'
         self.args.branch_name = 'b1'