[flake8] Resolving E4?? errors (#3817)
[flake8] Resolving E4?? errors (#3817)


dmigo/incubator-superset,alanmcruickshank/superset-dev,mistercrunch/panoramix,airbnb/caravel,dmigo/incubator-superset,airbnb/superset,alanmcruickshank/superset-dev,dmigo/incubator-superset,apache/incubator-superset,dmigo/incubator-superset,timifasubaa/incubator-superset,airbnb/superset,apache/incubator-superset,airbnb/superset,zhouyao1994/incubator-superset,airbnb/caravel,zhouyao1994/incubator-superset,zhouyao1994/incubator-superset,mistercrunch/panoramix,airbnb/superset,timifasubaa/incubator-superset,timifasubaa/incubator-superset,apache/incubator-superset,apache/incubator-superset,zhouyao1994/incubator-superset,airbnb/caravel,alanmcruickshank/superset-dev,mistercrunch/panoramix,timifasubaa/incubator-superset,zhouyao1994/incubator-superset,airbnb/caravel,alanmcruickshank/superset-dev,apache/incubator-superset,mistercrunch/panoramix