update copyright for conftest.py

test/conftest.py

-__copyright__ = "Copyright (C) 2019 Timothy A. Smith"
+__copyright__ = """
+Copyright (C) 2010-2019 Timothy A. Smith, Andreas Kloeckner,
+Holger Krekel and pytest-dev team
+"""
 
 __license__ = """
 Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -31,9 +34,9 @@ import utilities as u
 
 # {{{ mark for slow tests
 
-# setup to mark slow tests with @pytest.mark.slow, so that they don't run by
+# Setup to mark slow tests with @pytest.mark.slow, so that they don't run by
 # default, but can be forced to run with the command-line option --runslow
-# taken from
+# Taken from
 # https://docs.pytest.org/en/latest/example/simple.html#control-skipping-of-tests-according-to-command-line-option
 
 def pytest_addoption(parser):