Use new pytest mark API

Process each mark separately, rather than relying on automatic merging
of args and kwargs.

See https://docs.pytest.org/en/latest/mark.html#updating-code

This requires pytest 3.6, which does not run on python 2.6. Travis
environments have pytest 3.4 installed by default; this needs to be
explicitly updated.

Fixes #2

.travis.yml

@@ -2,14 +2,14 @@
 
 language: python
 python:
-  - 2.6
   - 2.7
   - 3.4
   - 3.5
   - 3.6
   - pypy
 
 install:
+  - pip install --upgrade pytest
   - pip install coveralls
 
 script:

pytest_datafiles.py

@@ -66,16 +66,20 @@ def datafiles(request, tmpdir):
     pytest fixture to define a 'tmpdir' containing files or directories
     specified with a 'datafiles' mark.
     """
-    if 'datafiles' not in request.keywords:
-        return tmpdir
-    content = request.keywords.get('datafiles').args
+    content = []
     options = {
         'keep_top_dir': False,
         'on_duplicate': 'exception',  # ignore, overwrite
         }
-    options.update(request.keywords.get('datafiles').kwargs)
+    for mark in request.node.iter_markers('datafiles'):
+        content.extend(mark.args)
+        options.update(mark.kwargs)
     on_duplicate = options['on_duplicate']
     keep_top_dir = options['keep_top_dir']
+
+    if not content:
+        return tmpdir
+
     if keep_top_dir not in (True, False):
         raise ValueError("'keep_top_dir' must be True or False")
     if on_duplicate not in ('exception', 'ignore', 'overwrite'):

setup.py

@@ -13,7 +13,7 @@ def _read(fname):
 
 DEPENDENCIES = [
     'py',
-    'pytest',
+    'pytest~=3.6',
     ]
 
 DESCRIPTION = ("py.test plugin to create a 'tmpdir' containing predefined "
@@ -43,7 +43,6 @@ def _read(fname):
         'Intended Audience :: Developers',
         'License :: OSI Approved :: MIT License',
         'Operating System :: OS Independent',
-        'Programming Language :: Python :: 2.6',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.4',

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py26, py27, py34, py35, py36
+envlist = py27, py34, py35, py36
 
 [testenv]
 commands = py.test tests/test_pytest_datafiles.py