Enumerate ignored flake8 rules

We were previously ignoring all F* and H* rules; this patch specifically
identifies them so that we can eliminate them one by one, without
introducing regressions along the way.

Change-Id: Iaf9ee17acf44aba1c93c1af50c84bd8216544b89

tox.ini

@@ -27,6 +27,23 @@ commands = python setup.py testr --coverage --testr-args='{posargs}'
 downloadcache = ~/cache/pip
 
 [flake8]
-ignore = E711,E712,E125,E126,F,H
+# E125: continuation line does not distinguish itself from next logical line
+# E126: continuation line over-indented for hanging indent
+# F401: imported but unused
+# F811: redefinition of unused 'client' from line 81
+# F821: undefined name
+# F841: local variable is assigned to but never used
+# F999: syntax error in doctest
+# H201: no 'except:' at least use 'except Exception:'
+# H202: assertRaises Exception too broad
+# H302: import only modules
+# H304: no relative imports
+# H306: imports not in alphabetical order
+# H401: docstring should not start with a space
+# H402: one line docstring needs punctuation.
+# H403: multi line docstring end on new line
+# H404: multi line docstring should start with a summary
+# H802: git commit title
+ignore = E125,E126,F401,F811,F821,F841,F999,H201,H202,H302,H304,H306,H401,H402,H403,H404,H802
 show-source = True
 exclude = .venv,.tox,dist,doc,*egg