remove package imports out of __init__.py?

[chriddyp]

I'm still getting an error related to #2 when installing from CI:

    ERROR: Complete output from command python setup.py egg_info:
    ERROR: Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-install-_RFpWn/dash-enterprise-auth/setup.py", line 3, in <module>
        setup()
      File "/home/circleci/repo/venv/lib/python2.7/site-packages/setuptools/__init__.py", line 145, in setup
        return distutils.core.setup(**attrs)
      File "/usr/local/lib/python2.7/distutils/core.py", line 124, in setup
        dist.parse_config_files()
      File "/home/circleci/repo/venv/lib/python2.7/site-packages/setuptools/dist.py", line 698, in parse_config_files
        ignore_option_errors=ignore_option_errors)
      File "/home/circleci/repo/venv/lib/python2.7/site-packages/setuptools/config.py", line 120, in parse_configuration
        meta.parse()
      File "/home/circleci/repo/venv/lib/python2.7/site-packages/setuptools/config.py", line 425, in parse
        section_parser_method(section_options)
      File "/home/circleci/repo/venv/lib/python2.7/site-packages/setuptools/config.py", line 398, in parse_section
        self[name] = value
      File "/home/circleci/repo/venv/lib/python2.7/site-packages/setuptools/config.py", line 183, in __setitem__
        value = parser(value)
      File "/home/circleci/repo/venv/lib/python2.7/site-packages/setuptools/config.py", line 513, in _parse_version
        version = self._parse_attr(value, self.package_dir)
      File "/home/circleci/repo/venv/lib/python2.7/site-packages/setuptools/config.py", line 348, in _parse_attr
        module = import_module(module_name)
      File "/usr/local/lib/python2.7/importlib/__init__.py", line 37, in import_module
        __import__(name)
      File "/tmp/pip-install-_RFpWn/dash-enterprise-auth/dash_enterprise_auth/__init__.py", line 14, in <module>
        import dash_core_components as _dcc
    ImportError: No module named dash_core_components
    ----------------------------------------
ERROR: Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-install-_RFpWn/dash-enterprise-auth/

Explanation here: https://stackoverflow.com/a/11015904/4142536