More strict PEP 8 check
db engine created on worker process init
Handle some exceptions

IntegrityError, FlushError and MultipleResultsFound exception are now handled.
This commit is functional.
Merge pull request #6 from dahlia/pep8

More strict PEP 8 check
Fix line 139: from url to destination_url
add award, genre and columns to work.
Fix indentation of migration script.
Stylistic adjustment.
Add migration script
Fix misindentation.
Merge pull request #4 from sjw0687/work

add award, genre and columns to work.
Merge remote-tracking branch 'upstream/master' into sqlalchemy
More robust Entity
Add tvtropes Redirections
download authors to sqlite
add requirement SPARQLWrapper
disable db_test
Down all artists from dbpedia.org to sqlite.
added .format()
delete contest, adopt pep8, change separator from ',' to '\\n', delete useless code and imports, add PyLD to eliminate wrarning