language: python
python:
  - "3.6"
  - "3.7"
  - "3.8"
install:
  - pip install networkx
  - pip install numpy
  - pip install pandas
  - pip install sympy
  - pip install pytest
  - python setup.py install
script:
  - pytest -v

language: python
before_install:
  - sudo apt install gfortran
python:
  - "3.6"
  - "3.7"
  - "3.8"
install:
  - pip install networkx
  - pip install numpy
  - pip install pandas
  - pip install sympy
  - pip install pytest
  - python setup.py install
script:
  - pytest -v

Add `gfortran` to Travis CI dependencies
TST: Add `gfortran` to Travis CI dependencies
