Use pytest-xdist for parallel tests (#45)

Author: ryanjulian

.travis.yml

@@ -37,7 +37,7 @@ script:
   - flake8 --version
   - flake8 src
   - flake8 --exclude=src,docs --extend-ignore=D
-  - pytest --cov=akro
+  - pytest -n $(nproc) --cov=akro
   - pushd docs && make html && popd
 
 after_script:

setup.py

@@ -28,8 +28,9 @@
     # See https://gitlab.com/pycqa/flake8-docstrings/issues/36
     'pydocstyle<4.0.0',
     'pylint',
-    'pytest>=3.6',  # Required for pytest-cov on Python 3.6
+    'pytest>=4.4.0',  # Required for pytest-xdist
     'pytest-cov',
+    'pytest-xdist',
     'sphinx',
     'recommonmark',
     'yapf',