As noted in #158, the default memory limit for yarn:pack jobs is a
little tight. In uis/devops/tools/gitlab-utils!214 it was noted that
1.5Gi suffices for a relatively simple TypeScript -> static site
application and so set the limit conservatively to 2Gi expecting other
uses to be a little more complex.

It's likely we'll need to bump this over time but this is at least a
limit observed to suffice for one user.

Tested with the smaller 1.5Gi limit in uis/devops/tools/gitlab-utils!214

Closes #158

fix(yarn): bump k8s memory limit for yarn:pack jobs

Closes #158

See merge request !201