Enable H407,H305,H307,E122 ignore E123

After bumping the hacking version to the 0.9.x series ignores were
added for several rules. This commit fixes the violations for a subset
of these rules and re-enables the checks.

E123 is ignored because this rule is ignored in the default pep8 by
default, due to a lack of consensus around it.

Change-Id: I8f14cd2ca6afc38d3fe8ee758272071111022896
diff --git a/tools/check_logs.py b/tools/check_logs.py
index bc4eaca..eab9f73 100755
--- a/tools/check_logs.py
+++ b/tools/check_logs.py
@@ -22,6 +22,7 @@
 import StringIO
 import sys
 import urllib2
+
 import yaml
 
 
diff --git a/tools/colorizer.py b/tools/colorizer.py
index a3a0616..e7152f2 100755
--- a/tools/colorizer.py
+++ b/tools/colorizer.py
@@ -42,10 +42,10 @@
 """Display a subunit stream through a colorized unittest test runner."""
 
 import heapq
-import subunit
 import sys
 import unittest
 
+import subunit
 import testtools
 
 
diff --git a/tools/find_stack_traces.py b/tools/find_stack_traces.py
index c905976..4862d01 100755
--- a/tools/find_stack_traces.py
+++ b/tools/find_stack_traces.py
@@ -16,12 +16,13 @@
 #    under the License.
 
 import gzip
+import pprint
 import re
 import StringIO
 import sys
 import urllib2
 
-import pprint
+
 pp = pprint.PrettyPrinter()
 
 NOVA_TIMESTAMP = r"\d\d\d\d-\d\d-\d\d \d\d:\d\d:\d\d\.\d\d\d"