Update doc/topics/tutorials/bootstrap_ec2.rst
Update doc/topics/tutorials/bootstrap_ec2.rst

'E: Unable to locate package salt'

I think you have to install `salt-master` and `salt-minion` packages as shown on the Ubuntu install page: http://docs.saltstack.org/en/latest/topics/installation/ubuntu.html

(I assume we're on Ubuntu since we're also using Canonical CloudInit and the `apt-get` command is used)
saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt