Run flake8 on travis
Run flake8 on travis

thewtex/tomviz,OpenChemistry/tomviz,mathturtle/tomviz,OpenChemistry/tomviz,mathturtle/tomviz,thewtex/tomviz,OpenChemistry/tomviz,cryos/tomviz,cryos/tomviz,cjh1/tomviz,cjh1/tomviz,cjh1/tomviz,OpenChemistry/tomviz,thewtex/tomviz,mathturtle/tomviz,cryos/tomviz