get environment creation working again in preparation for Fall 2016

[tobiasmcnulty]

• upgrade fabulaws (now more robust, will retry creation of failed instances)
• remove deprecated log_host
• updated less version (old version, 2.5.3, generates empty CSS files locally and on the servers)
• downsize instances for staging to avoid racking up a large bill

[dpoirier]

We were using large instances for staging because we were running load testing there. If we don't need to do that again, +1.

[tobiasmcnulty]

Hopefully not, but if it's needed I'll spin up a testing environment.

Thanks!