TEST: blueyed/pytest@fixture-stack

Ref: pytest-dev/pytest#6551

Author: blueyed

.travis.yml

@@ -98,7 +98,7 @@ install:
   - pip install tox==3.9.0
 
 script:
-  - tox
+  - tox --force-dep "pytest@git+https://github.com/blueyed/pytest@fixture-stack#egg=pytest"
 
 after_success:
   - |

tox.ini

@@ -27,6 +27,8 @@ deps =
     postgres: psycopg2-binary
     coverage: coverage-enable-subprocess
 
+    pytest
+
     pytest41: pytest>=4.1,<4.2
     pytest41: attrs==17.4.0
     xdist: pytest-xdist>=1.15