Resolve flake8 complaints

[stennie]

Outstanding warnings to resolve with tox -e flake8 before enabling by default per #547

1     C901 'MLaunchTool.init' is too complex (55)
36    E128 continuation line under-indented for visual indent
5     E129 visually indented line with same indent as next logical line
2     E201 whitespace after '('
2     E202 whitespace before ')'
42    E203 whitespace before ':'
10    E221 multiple spaces before operator
2     E225 missing whitespace around operator
10    E226 missing whitespace around arithmetic operator
6     E228 missing whitespace around modulo operator
48    E251 unexpected spaces around keyword / parameter equals
8     E265 block comment should start with '# '
9     E302 expected 2 blank lines, found 1
23    E303 too many blank lines (2)
116   E501 line too long (92 > 79 characters)
19    E711 comparison to None should be 'if cond is None:'
2     E713 test for membership should be 'not in'
2     E731 do not assign a lambda expression, use a def
13    F401 'queue' imported but unused
2     F811 redefinition of unused 'queue' from line 29
4     F821 undefined name 'plt'
56    F841 local variable 'is_csrs' is assigned to but never used
31    W291 trailing whitespace
6     W293 blank line contains whitespace
2     W391 blank line at end of file
12    W503 line break before binary operator
469

[stennie]

Fixed via #653