Refactor webpack file cleanup script to use ES6-compatible callback-style Node fs calls.
Refactor webpack file cleanup script to use ES6-compatible callback-style Node fs calls.

mark-rushakoff/influxdb,influxdata/influxdb,nooproblem/influxdb,li-ang/influxdb,influxdb/influxdb,mark-rushakoff/influxdb,mark-rushakoff/influxdb,influxdata/influxdb,influxdb/influxdb,influxdb/influxdb,nooproblem/influxdb,influxdb/influxdb,li-ang/influxdb,mark-rushakoff/influxdb,mark-rushakoff/influxdb,influxdb/influxdb,mark-rushakoff/influxdb,influxdb/influxdb,nooproblem/influxdb,nooproblem/influxdb,nooproblem/influxdb