machine:
  xcode:
    version: 8.3
  pre:
    # from https://discuss.circleci.com/t/virtualenv-error-on-osx-build/387/2
    - sudo -H pip install --upgrade virtualenv
dependencies:
  override:
    - brew install libyaml
    - brew install python
    - brew install python3
    - sudo -H pip install -r requirements_test.txt
compile:
  override:
test:
  environment:
    LC_ALL: "en_US.UTF-8"
    LANG: "en_US.UTF-8"
  override:
    - sudo -H tox

machine:
  xcode:
    version: 8.3
  pre:
    # from https://discuss.circleci.com/t/virtualenv-error-on-osx-build/387/2
    - sudo -H pip install --upgrade virtualenv
dependencies:
  override:
    - brew install libyaml
    - brew install python
    - brew install python3
    - sudo -H pip install -r requirements_test.txt
compile:
  override:
test:
  environment:
    LC_ALL: "en_US.UTF-8"
    LANG: "en_US.UTF-8"
  override:
    - sudo -H tox --develop

Use --develop flag for tox
Use --develop flag for tox
