Fix pep8 codestyle warnings

synapse/util/__init__.py

@@ -37,6 +37,7 @@ class Clock(object):
 
     def call_later(self, delay, callback):
         current_context = LoggingContext.current_context()
+
         def wrapped_callback():
             LoggingContext.thread_local.current_context = current_context
             callback()

synapse/util/async.py

@@ -18,6 +18,7 @@ from twisted.internet import defer, reactor
 
 from .logcontext import PreserveLoggingContext
 
+
 @defer.inlineCallbacks
 def sleep(seconds):
     d = defer.Deferred()
@@ -25,6 +26,7 @@ def sleep(seconds):
     with PreserveLoggingContext():
         yield d
 
+
 def run_on_reactor():
     """ This will cause the rest of the function to be invoked upon the next
     iteration of the main loop