admin: use Andrew's advice to migrate to a more cost-efficient AWS setup

[nolessafool]

@onewheelskyward is an AWS pro and looked quickly at our settings and suggests:

• change t2.micro to t3.micro

• use a 16G EBS

• use a reserved instance (for a year or 3)

• add swap

• save a bit of $ ($10 -> ~$5/mo).