build: Updating lodash to 4.17.15
build: Updating lodash to 4.17.15

* https://npmjs.com/advisories/1065
* CVE-2019-10744

Change-Id: If46ffacdf69e6d4e60e067f0961bbef9e39e1fcb

wikimedia/mediawiki-extensions-Arrays,wikimedia/mediawiki-extensions-Arrays