Using assert_outcomes as that is slightly safer

See #190 for context.

Author: nicoddemus

tests/test_pytest_mock.py

@@ -809,7 +809,7 @@ def test_foo(mocker):
     """
     )
     result = testdir.runpytest()
-    result.stdout.fnmatch_lines("* 1 passed*")
+    result.assert_outcomes(passed=1)
 
     kwargs = {"legacy": True}
     assert compileall.compile_file(str(py_fn), **kwargs)
@@ -819,7 +819,7 @@ def test_foo(mocker):
 
     py_fn.remove()
     result = testdir.runpytest()
-    result.stdout.fnmatch_lines("* 1 passed*")
+    result.assert_outcomes(passed=1)
 
 
 def test_used_with_class_scope(testdir):