Add paths option in local-plugins config file.

tests/integration/subdir/aplugin.py

@@ -0,0 +1,16 @@
+"""Module that is off sys.path by default, for testing local-plugin-paths."""
+
+
+class ExtensionTestPlugin2(object):
+    """Extension test plugin in its own directory."""
+
+    name = 'ExtensionTestPlugin2'
+    version = '1.0.0'
+
+    def __init__(self, tree):
+        """Construct an instance of test plugin."""
+        pass
+
+    def run(self):
+        """Do nothing."""
+        pass