old_contents: #!/usr/bin/env python
  
  #    Copyright 2017 Cargill Incorporated
  #
  #    Licensed under the Apache License, Version 2.0 (the "License");
  #    you may not use this file except in compliance with the License.
  #    You may obtain a copy of the License at
  #
  #      http://www.apache.org/licenses/LICENSE-2.0
  #
  #    Unless required by applicable law or agreed to in writing, software
  #    distributed under the License is distributed on an "AS IS" BASIS,
  #    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  #    See the License for the specific language governing permissions and
  #    limitations under the License.
  
  from setuptools import setup
  import unittest
  version = '0.1.0'
  
  def pipewrench_test_suite():
      test_loader = unittest.TestLoader()
      test_suite = test_loader.discover('pipewrench', pattern='*_test.py')
      return test_suite
  
  setup(name='pipewrench',
        version=version,
        description='Framework for building data pipelines',
        author='Cargill Inc',
        url='https://cargill.github.io/',
        install_requires=['jinja2', 'pyyaml', 'sdctool', 'pytest', 'pylint'],
        packages=['pipewrench'],
        test_suite='setup.pipewrench_test_suite',
        scripts=['pipewrench-merge']
        )
  
new_contents: #!/usr/bin/env python
  
  #    Copyright 2017 Cargill Incorporated
  #
  #    Licensed under the Apache License, Version 2.0 (the "License");
  #    you may not use this file except in compliance with the License.
  #    You may obtain a copy of the License at
  #
  #      http://www.apache.org/licenses/LICENSE-2.0
  #
  #    Unless required by applicable law or agreed to in writing, software
  #    distributed under the License is distributed on an "AS IS" BASIS,
  #    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  #    See the License for the specific language governing permissions and
  #    limitations under the License.
  
  from setuptools import setup
  import unittest
  version = '0.1.0'
  
  def pipewrench_test_suite():
      test_loader = unittest.TestLoader()
      test_suite = test_loader.discover('pipewrench', pattern='*_test.py')
      return test_suite
  
  setup(name='pipewrench',
        version=version,
        description='Framework for building data pipelines',
        author='Cargill Inc',
        url='https://cargill.github.io/',
        install_requires=['jinja2', 'pyyaml', 'sdctool', 'pytest', 'pylint', 'marshmallow'],
        packages=['pipewrench'],
        test_suite='setup.pipewrench_test_suite',
        scripts=['pipewrench-merge']
        )
  
subject: Add 'marshmallow' as a dependency in setup.py