William Chargin 98a039d340
backend: use Flow in Webpack config (#780)
Summary:
Over the past few commits, I have accidentally removed all Flow errors
from the Webpack config. We can now use Flow on that file to prevent any
new errors from creeping in.

Test Plan:
Running `yarn flow` suffices.

wchargin-branch: backend-flow
2018-09-05 12:03:30 -07:00
..
2018-09-02 16:11:56 -07:00