Fix blank line issues reported by flake8

- E301 expected 1 blank line
- E302 expected 2 blank lines
- E303 too many blank lines
- E305 expected 2 blank lines after class or function definition
- E306 expected 1 blank line before a nested definition

Fixed automatically with autopep8:

  git ls-files | grep py$ | xargs autopep8 --in-place \
    --select E301,E302,E303,E305,E306

Manually fix issues in project.py caused by misuse of block comments.

Change-Id: Iee840fcaff48aae504ddac9c3e76d2acd484f6a9
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/254599
Reviewed-by: Mike Frysinger <vapier@google.com>
Tested-by: David Pursehouse <dpursehouse@collab.net>

event_log.py

@@ -23,6 +23,7 @@ TASK_COMMAND = 'command'
 TASK_SYNC_NETWORK = 'sync-network'
 TASK_SYNC_LOCAL = 'sync-local'
 
+
 class EventLog(object):
   """Event log that records events that occurred during a repo invocation.
 
@@ -165,6 +166,7 @@ class EventLog(object):
 # An integer id that is unique across this invocation of the program.
 _EVENT_ID = multiprocessing.Value('i', 1)
 
+
 def _NextEventId():
   """Helper function for grabbing the next unique id.