Revert cibuildwheel pinning

Author: rnpridgeon

.travis.yml

@@ -58,7 +58,7 @@ install:
  - if [[ $TRAVIS_OS_NAME == "osx" ]]; then python -m ensurepip && virtualenv /tmp/venv && source /tmp/venv/bin/activate ; fi
  - if [[ -z $CIBW_BEFORE_BUILD ]]; then pip install pytest-timeout flake8 ; fi
  - if [[ -z $CIBW_BEFORE_BUILD ]]; then rm -rf tmp-build ; tools/bootstrap-librdkafka.sh --require-ssl ${LIBRDKAFKA_VERSION} tmp-build ; fi
- - if [[ -n $TRAVIS_TAG && -n $CIBW_BEFORE_BUILD ]]; then pip install 'cibuildwheel==v0.10.0' --force-reinstall; fi
+ - if [[ -n $TRAVIS_TAG && -n $CIBW_BEFORE_BUILD ]]; then pip install cibuildwheel --force-reinstall; fi
 
 script:
  - if [[ -z $CIBW_BEFORE_BUILD ]]; then pip install -v --global-option=build_ext --global-option="-Itmp-build/include/" --global-option="-Ltmp-build/lib" . .[avro] ; fi