Use pytest from fork to test bug fix in pytest

Related to pytest-dev/pytest#1888

.travis.yml

@@ -12,7 +12,7 @@ env:
  - LC_ALL=C LC_CTYPE=C
 script:
  # avoid VersionConflict when newer version is required
- - pip install -U 'pytest>=2.8,<3'
+ - pip install -U git+https://github.com/nicoddemus/pytest@find-spec-rewrite-hook
 
  # Output the env, because the travis docs just can't be trusted
  - env

setup.py

@@ -181,7 +181,7 @@ def pypi_link(pkg_filename):
     tests_require=[
         'setuptools[ssl]',
         'pytest-flake8',
-        'pytest>=2.8,<3',
+        'pytest>=2.8',
     ] + (['mock'] if sys.version_info[:2] < (3, 3) else []),
     setup_requires=[
     ] + pytest_runner + wheel,