build: Explicitly depend on eslint-config-wikimedia, don't just hope it's there

Authored by Jdforrester-WMF on Apr 21 2017, 12:01 AM.

Description

build: Explicitly depend on eslint-config-wikimedia, don't just hope it's there

Change-Id: I95871f4180682e34c16f7e4fa1171380509816b5