pep8 linting (whitespaces)

W191 indentation contains tabs
E221 multiple spaces before operator
E222 multiple spaces after operator
E225 missing whitespace around operator
E271 multiple spaces after keyword
W292 no newline at end of file
W293 blank line contains whitespace
W391 blank line at end of file
pep8 linting (blank lines expectations)

E301 expected 1 blank line, found 0
E302 expected 2 blank lines, found 1
E303 too many blank lines (n)
pep8 linting (whitespace before/after)

E201 whitespace after '('
E202 whitespace before ')'
E203 whitespace before ':'
E225 missing whitespace around operator
E226 missing whitespace around arithmetic operator
E227 missing whitespace around bitwise or shift operator
E228 missing whitespace around modulo operator
E231 missing whitespace after ','
E241 multiple spaces after ','
E251 unexpected spaces around keyword / parameter equals
pep8 linting (double spaces before comment)

E261 at least two spaces before inline comment
pep8 linting (trailing whitespace)

W291 trailing whitespace
Merge pull request #204 from hashar/pep8-linting

Pep8 linting