change ma-length-of-line to 120
Merge pull request #32 from niyaton/fix-pep8-max-length-of-line

change ma-length-of-line to 120
pep8 to distiller.py
pep8 to diff.py
pep8 to tree_contents.py
pep8 to pull_up_method.py
pep8 to extract_method.py
pep8 to shingles_test.py
pep8 to refactoring_detection.py but still have problems
pep8 to parser.py
followed PEP8
followed PEP8
followed PEP8
followed PEP8
followed PEP8
followed PEP8
followed PEP8
followed PEP8
followed PEP8
followed PEP8: pull_up_method.py