Splitting provision_machine into the provisioning part and bootstrap_machine. (#231)
get_instance_by_tag -> get_instance_by_tags. (#231)
Due to splitting of bootstrap phase, we can now provision with ami user. (#231)

This is because ami user is also a sudoer. By designs, most
interactions with the machines (except for bootstrapping) should be
done with the ami user.
Added task for connecting to a machine given its EC2 name. (#231)
Added task for refreshing code on the machines. (#231)
Added task for  reprovisioning the machines via puppet. (#231)

It's now feasible to do this because bootstrap isn't repeated for each
machine anymore.
Using hostnames for settings_local instead of string representations of instances. (#231)
Lines of settings_local should be appended and not overwrite the content. (#231)
Added task for finding out the host of a given instance by name. (#231)