Fix PyTest class in setup.py.

It should be subclass of `setuptools.command.test`. Also, use it in
.travis.yml.

.travis.yml

@@ -6,10 +6,8 @@ python:
   - "3.4"
   - "pypy"
 install:
-  - "pip install -r requirements_dev.txt"
-  - "python setup.py install"
   - if [[ $TRAVIS_PYTHON_VERSION == 3* ]]; then pip install aiohttp; fi
-script: py.test -x tests/
+script: python setup.py test
 branches:
   only:
     - master

requirements_dev.txt

@@ -1,5 +1,5 @@
-py==1.4.19
-pytest==2.5.1
-pytest-cov==1.6
+py==1.4.22
+pytest==2.6.0
+pytest-cov==1.7.0
 sphinx
 sphinx_rtd_theme

setup.py

@@ -5,7 +5,9 @@
 
 
 import os
-from setuptools import setup, Command
+from setuptools import setup
+from setuptools.command.test import test as TestCommand
+
 import sys
 
 from gunicorn import __version__
@@ -46,25 +48,26 @@ fname = os.path.join(os.path.dirname(__file__), 'requirements_dev.txt')
 with open(fname) as f:
     tests_require = list(map(lambda l: l.strip(), f.readlines()))
 
-class PyTest(Command):
+class PyTest(TestCommand):
     user_options = [
         ("cov", None, "measure coverage")
     ]
 
     def initialize_options(self):
+        TestCommand.initialize_options(self)
         self.cov = None
 
     def finalize_options(self):
-        pass
-
-    def run(self):
-        import subprocess
-        basecmd = [sys.executable, '-m', 'pytest']
+        TestCommand.finalize_options(self)
+        self.test_args = ['tests']
         if self.cov:
-            basecmd += ['--cov', 'gunicorn']
-        errno = subprocess.call(basecmd + ['tests'])
-        raise SystemExit(errno)
+            self.test_args += ['--cov', 'gunicorn']
+        self.test_suite = True
 
+    def run_tests(self):
+        import pytest
+        errno = pytest.main(self.test_args)
+        sys.exit(errno)
 
 REQUIREMENTS = []