autopep8 to codebase
manual fixes for PEP8 E711,E712
fix removed significant trailing whitespace in multiline string
add pep8 tests to Travis tests
towards manually fixing E501
autopep8 to fix upstream changes
towards manually fixing E501
manual PEP8 fixes
remove some trailing whitespace
cleanup mathics/core/expression.py pep8
manual E501 fixes
more manual E501 fixes
manual E501 fixes
tidy main.py pep8 changes
use pep8bot in favour of pep8.py to test pep8 compliance
correct various issues reported by pyflakes