:fly: `create_jenkins_job.py` doesn't support `empy>=4`

Description

Running python3 create_jenkins_job.py ... using empy >= 4 leads to the following error:

Connecting to Jenkins 'https://ci.ros2.org'
Connected to Jenkins version '2.319.2'
CompatibilityError processing template 'ci_job.xml.em'
Traceback (most recent call last):
  File "/home/agali/tmp/deploy_ros_buildfarm/venv/lib/python3.6/site-packages/ros_buildfarm/templates/__init__.py", line 76, in expand_template
    interpreter = CachingInterpreter(output=output, options=options)
  File "/home/agali/tmp/deploy_ros_buildfarm/venv/lib/python3.6/site-packages/em.py", line 4369, in __init__
    raise CompatibilityError("unrecognized Interpreter constructor keyword arguments; when calling expand, use locals dictionary instead of keywords: %s" % badKeys, keys=badKeys)
em.CompatibilityError: unrecognized Interpreter constructor keyword arguments; when calling expand, use locals dictionary instead of keywords: ['options']

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "create_jenkins_job.py", line 549, in <module>
    main()
  File "create_jenkins_job.py", line 190, in main
    'test_args_default': os_configs.get(os_name, {}).get('test_args_default', data['test_args_default']) + ' --executor sequential',
  File "create_jenkins_job.py", line 176, in create_job
    job_config = expand_template(template_file, job_data)
  File "/home/agali/tmp/deploy_ros_buildfarm/venv/lib/python3.6/site-packages/ros_buildfarm/templates/__init__.py", line 110, in expand_template
    interpreter.shutdown()
AttributeError: 'NoneType' object has no attribute 'shutdown'

Using empy==3.3.4 solved this problem