Devise deployment strategy for instance brought up by the autoscaler

[xmunoz]

When new EC2 instances are brought up by the autoscaler, they will most likely have old code on them. Define a strategy by which a code deployment can happen on these instances as part of the instance creation lifecycle.

[cecilia-donnelly]

@andrewatwood and I believe this is referring to code deploys - we won't build a new image for every code change, so how do we make sure that the new code gets pushed out to every instance in the autoscaling group?

[cecilia-donnelly]

We think that fixing #21 will be mostly enough to manage this, or at least is a good place to start.

[xmunoz]

#24 needs to happen before this can. An early attempt at this can be found in #80