tox/setup.py: remove _PYTEST_SETUP_SKIP_PLUGGY_DEP=1 hack

setup.py

@@ -1,5 +1,3 @@
-import os
-
 from setuptools import setup
 
 # TODO: if py gets upgrade to >=1.6,
@@ -15,15 +13,10 @@ INSTALL_REQUIRES = [
     'funcsigs;python_version<"3.0"',
     'pathlib2>=2.2.0;python_version<"3.6"',
     'colorama;sys_platform=="win32"',
+    "pluggy>=0.7",
 ]
 
 
-# if _PYTEST_SETUP_SKIP_PLUGGY_DEP is set, skip installing pluggy;
-# used by tox.ini to test with pluggy master
-if "_PYTEST_SETUP_SKIP_PLUGGY_DEP" not in os.environ:
-    INSTALL_REQUIRES.append("pluggy>=0.7")
-
-
 def main():
     setup(
         use_scm_version={"write_to": "src/_pytest/_version.py"},

tox.ini

@@ -42,9 +42,6 @@ setenv =
     pexpect: _PYTEST_TOX_PLATFORM=linux|darwin
     pexpect: _PYTEST_TOX_POSARGS_PEXPECT=testing/test_pdb.py testing/test_terminal.py testing/test_unittest.py
 
-    # TODO: remove?!
-    pluggymaster: _PYTEST_SETUP_SKIP_PLUGGY_DEP=1
-
     xdist: _PYTEST_TOX_POSARGS_XDIST=-n auto
 extras = testing
 deps =