Integrate fixture funcs into single one.

And place the new, integrated fixture on top. We keep it in this
module (instead of moving it to conftest.py) because it contains
functionality related to randomsources only.

tests/test_random_sources.py

@@ -11,6 +11,16 @@ from diceware.random_sources import (
     )
 
 
+@pytest.fixture(scope="function")
+def fake_input(request, monkeypatch):
+    def handler(values):
+        mock = InputMock(values)
+        monkeypatch.setattr(
+            "diceware.random_sources.input_func", mock)
+        return mock
+    return handler
+
+
 class TestSystemRandomSource(object):
 
     def test_options_are_stored(self):
@@ -68,20 +78,6 @@ class TestSystemRandomSource(object):
         assert num > 0
 
 
-def fake_input_values(values, patch):
-    input_mock = InputMock(values)
-    patch.setattr(
-        "diceware.random_sources.input_func", input_mock)
-    return input_mock
-
-
-@pytest.fixture(scope="function")
-def fake_input(request, monkeypatch):
-    def handler(values):
-        return fake_input_values(values, monkeypatch)
-    return handler
-
-
 class TestRealDiceRandomSource(object):
 
     def test_raw_input_patch_works(self, capsys, fake_input):