Flake8 fixes (#35)

* Apply Flake8 also on `setup.py`

modified:   tox.ini

* Fix W605 - invalid escape syntax

modified:   packages/setup.py
modified:   tox.ini

* Update comment about Flake8: W504

W503 and W504 are mutual exclusive - so we have to keep one of them.

modified:   tox.ini

* Fix F841 - variable assigned but never used

modified:   ssh-audit.py
modified:   tox.ini

* Fix E741 - ambiguous variable name 'l'

modified:   ssh-audit.py
modified:   tox.ini

* Fix E712 - comparison to False should be 'if cond is False'

... and not 'if conf == False'.

modified:   ssh-audit.py
modified:   tox.ini

* Fix E711 - comparison to None should be 'if cond is not None'

... and not 'if cond != None'.

modified:   ssh-audit.py
modified:   tox.ini

* Fix E305 - expected 2 blank lines

... after class or function definition, found 1.

modified:   ssh-audit.py
modified:   tox.ini

* Fix E303 - too many blank lines

modified:   ssh-audit.py
modified:   tox.ini

* Fix E303 - too many blank lines

modified:   ssh-audit.py
modified:   tox.ini

* Fix E301 - expected 1 blank line, found 0

No code change necessary, probably fixed by another commit.

modified:   tox.ini

* Fix E265 - block comment should start with '# '

There is lots of commented out code, which usually should be just
deleted.

I will keep it for now, as I am not yet very familiar with the code
base.

modified:   ssh-audit.py
modified:   tox.ini

* Fix E261 - at least two spaces before inline comment

modified:   ssh-audit.py
modified:   tox.ini

* Fix E251 - unexpected spaces around keyword / parameter equals

modified:   packages/setup.py
modified:   tox.ini

* Fix E231 - missing whitespace after ','

No code change necessary, probably fixed by previous commit.

modified:   tox.ini

* Fix E226 - missing whitespace around arithmetic operator

modified:   ssh-audit.py
modified:   tox.ini

* Fix W293 - blank line contains whitespace

modified:   ssh-audit.py
modified:   tox.ini

* Fix E221 - multiple spaces before operator

modified:   ssh-audit.py
modified:   tox.ini

* Update comment about Flake 8 E241

Lots of data is formatted as tables, so this warning is disabled for a
good reason.

modified:   tox.ini

* Fix E401 - multiple imports on one line

modified:   ssh-audit.py
modified:   tox.ini

* Do not ignore Flake8 warning F401

... as there were no errors in source code anyway.

modified:   tox.ini

* Fix F821 - undefined name

modified:   ssh-audit.py
modified:   tox.ini

* Reformat ignore section for Flake8

modified:   tox.ini

* Flake8 test suite

modified:   test/conftest.py
modified:   test/test_auditconf.py
modified:   test/test_banner.py
modified:   test/test_buffer.py
modified:   test/test_errors.py
modified:   test/test_output.py
modified:   test/test_resolve.py
modified:   test/test_socket.py
modified:   test/test_software.py
modified:   test/test_ssh1.py
modified:   test/test_ssh2.py
modified:   test/test_ssh_algorithm.py
modified:   test/test_utils.py
modified:   test/test_version_compare.py
modified:   tox.ini

tox.ini

@@ -80,7 +80,7 @@ commands =
 deps =
 	flake8
 commands =
-	flake8 {posargs:{env:SSHAUDIT}}
+	flake8 {posargs:{env:SSHAUDIT} {toxinidir}/packages/setup.py {toxinidir}/test}  --statistics
 
 [testenv:vulture]
 deps =
@@ -137,42 +137,13 @@ max-module-lines = 2500
 
 [flake8]
 ignore =
-	# indentation contains tabs
-	W191,
-	# blank line contains whitespace
-	W293,
-	# indentation contains mixed spaces and tabs
-	E101,
-	# multiple spaces before operator
-	E221,
-	# multiple spaces after operator
-	E241,
-	# multiple imports on one line
-	E401,
-	# line too long
-	E501,
-	# module imported but unused
-	F401,
-	# undefined name
-	F821,
-	# these exceptions should be handled one by one
-	E117, # over-indented
-	E126, # continuation line over-indented for hanging indent
-	E128, # continuation line under-indented for visual indent
-	E226, # missing whitespace around arithmetic operator
-	E231, # missing whitespace after ','
-	E251, # unexpected spaces around keyword / parameter equals
-	E261, # at least two spaces before inline comment
-	E265, # block comment should start with '# '
-	E301, # expected 1 blank line, found 0
-	E302, # expected 2 blank lines, found 1
-	E303, # too many blank lines (2)
-	E305, # expected 2 blank lines after class or function definition, found 1
-	E711, # comparison to None should be 'if cond is not None:'
-	E712, # comparison to False should be 'if cond is False:' or 'if not cond:'
-	E722, # do not use bare 'except'
-	E741, # ambiguous variable name 'l'
-	F601, # dictionary key 'ecdsa-sha2-1.3.132.0.10' repeated with different values
-	F841, # local variable 'e' is assigned to but never used
-	W504, # line break after binary operator
-	W605, # invalid escape sequence '\s'
+	W191,  # indentation contains tabs
+	E101,  # indentation contains mixed spaces and tabs
+	E241,  # multiple spaces after operator; should be kept for tabular data
+	E501,  # line too long
+	E117,  # over-indented
+	E126,  # continuation line over-indented for hanging indent
+	E128,  # continuation line under-indented for visual indent
+	E722,  # do not use bare 'except'
+	F601,  # dictionary key 'ecdsa-sha2-1.3.132.0.10' repeated with different values
+	W504,  # line break after binary operator; this (or W503) has to stay