n1->e2-migration

[macribas]

As requested by Sam, we need to use e2 instances whenever possible. There is a project going on, to go through each lab and replace the instance types by their e2 equivalent ones. I just did that with this repo.

[rosera]

As requested by Sam, we need to use e2 instances whenever possible. There is a project going on, to go through each lab and replace the instance types by their e2 equivalent ones. I just did that with this repo.

The default Google Cloud machines remain N1 per the documentation. Where practical we will update to E2 series in the active code.