Rename testsuite to tests and suggestions

Remove  py.test from setup.py install_requires
Rename testsuite folder to tests.
diff --git a/setup.py b/setup.py
index 7b3b7b6..2cf3106 100644
--- a/setup.py
+++ b/setup.py
@@ -72,10 +72,7 @@
         'Topic :: Text Processing :: Markup :: HTML'
     ],
     packages=['jinja2'],
-    install_requires=[
-        'MarkupSafe',
-        'pytest'
-    ],
+    install_requires=['MarkupSafe'],
     extras_require={'i18n': ['Babel>=0.8']},
     include_package_data=True,
     entry_points="""