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>

subcmds/sync.py

@@ -53,6 +53,7 @@ except ImportError:
 
 try:
   import resource
+
   def _rlimit_nofile():
     return resource.getrlimit(resource.RLIMIT_NOFILE)
 except ImportError:
@@ -81,13 +82,16 @@ from manifest_xml import GitcManifest
 
 _ONE_DAY_S = 24 * 60 * 60
 
+
 class _FetchError(Exception):
   """Internal error thrown in _FetchHelper() when we don't want stack trace."""
   pass
 
+
 class _CheckoutError(Exception):
   """Internal error thrown in _CheckoutOne() when we don't want stack trace."""
 
+
 class Sync(Command, MirrorSafeCommand):
   jobs = 1
   common = True
@@ -1044,6 +1048,7 @@ later is required to fix a server side protocol bug.
             file=sys.stderr)
       sys.exit(1)
 
+
 def _PostRepoUpgrade(manifest, quiet=False):
   wrapper = Wrapper()
   if wrapper.NeedSetupGnuPG():
@@ -1052,6 +1057,7 @@ def _PostRepoUpgrade(manifest, quiet=False):
     if project.Exists:
       project.PostRepoUpgrade()
 
+
 def _PostRepoFetch(rp, no_repo_verify=False, verbose=False):
   if rp.HasChanges:
     print('info: A new version of repo is available', file=sys.stderr)
@@ -1070,6 +1076,7 @@ def _PostRepoFetch(rp, no_repo_verify=False, verbose=False):
       print('repo version %s is current' % rp.work_git.describe(HEAD),
             file=sys.stderr)
 
+
 def _VerifyTag(project):
   gpg_dir = os.path.expanduser('~/.repoconfig/gnupg')
   if not os.path.exists(gpg_dir):
@@ -1174,6 +1181,8 @@ class _FetchTimes(object):
 # and supporting persistent-http[s]. It cannot change hosts from
 # request to request like the normal transport, the real url
 # is passed during initialization.
+
+
 class PersistentTransport(xmlrpc.client.Transport):
   def __init__(self, orig_host):
     self.orig_host = orig_host