move webpack-dev-server to devDependencies, update webpack to ^4.29.6
move webpack-dev-server to devDependencies, update webpack to ^4.29.6

DemocracyLab/CivicTechExchange,DemocracyLab/CivicTechExchange,DemocracyLab/CivicTechExchange,DemocracyLab/CivicTechExchange