Fix some more pylint issues.

backive/core/events.py

@@ -1,3 +1,7 @@
+"""
+TODO
+"""
+
 import os
 import asyncio
 

backive/core/scheduler.py

@@ -5,6 +5,9 @@ from datetime import datetime
 
 
 class Scheduler():
+    """
+    TODO
+    """
     __shared_state = dict()
     __data = dict()
     def __init__(self):

backive/core/tool.py

@@ -4,6 +4,9 @@ import os
 AVAILABLE_TOOLS = {}
 
 def register_tool(name):
+    """
+    TODO
+    """
     def decorator(Cls):
         AVAILABLE_TOOLS.update({name: Cls})
     return decorator

backive/tools/rsync.py

@@ -3,5 +3,8 @@ from backive.core.tool import AVAILABLE_TOOLS, register_tool
 
 @register_tool("rsync")
 class Rsync:
+    """
+    TODO
+    """
     def __init__(self, options):
         pass

tests/test_events.py

@@ -10,6 +10,9 @@ from backive.core.events import EventInterface
 
 
 class TestEvents(unittest.TestCase):
+    """
+    TODO
+    """
     def set_data(self, data):
         self.data = data