Fixed circular imports hangs pypy

[wearpants]

Very odd: https://travis-ci.org/wearpants/twiggy/jobs/425441522

============================= test session starts ==============================
platform linux2 -- Python 2.7.13[pypy-5.8.0-final], pytest-3.8.0, py-1.6.0, pluggy-0.7.1
rootdir: /home/travis/build/wearpants/twiggy, inifile:
plugins: mock-1.10.0, env-info-0.3.0, cov-2.6.0
collected 310 items                                                            
tests/test_converter.py .................                                [  5%]
tests/test_dict_config.py .....                                          [  7%]
tests/test_filters.py .............                                      [ 11%]
tests/test_formats.py ........                                           [ 13%]
tests/test_globals.py ..........                                         [ 17%]
tests/test_integration.py .                                              [ 17%]
tests/test_levels.py ...............                                     [ 22%]
tests/test_lib.py ..                                                     [ 22%]
tests/test_lib_validators.py ...............................             [ 32%]
tests/test_logger.py ....................
No output has been received in the last 10m0s, this potentially indicates a stalled build or something wrong with the build itself.
Check the details on how to adjust your build configuration on: https://docs.travis-ci.com/user/common-build-problems/#Build-times-out-because-no-output-was-received
The build has been terminated

[abadger]

Hmmm... and it appears to be a transient failure as well....

[wearpants]

blames travis, moves on