Bug 1399281 - Vagrant: Use --ignore-engines with yarn install
Bug 1399281 - Vagrant: Use --ignore-engines with yarn install

To prevent errors when Vagrant provisioning after a new nodejs
version is released, due to version mismatch between package.json
(used by Heroku) and the APT package used by Vagrant. The other
option is pinning the version in Vagrant too, however we might as
well wait until the Docker based development environment where
state management/invalidation is simpler.

tojon/treeherder,KWierso/treeherder,tojonmz/treeherder,tojonmz/treeherder,KWierso/treeherder,tojonmz/treeherder,KWierso/treeherder,KWierso/treeherder,edmorley/treeherder,tojonmz/treeherder,tojon/treeherder,edmorley/treeherder,tojon/treeherder,edmorley/treeherder,tojonmz/treeherder,tojon/treeherder,edmorley/treeherder,tojonmz/treeherder