update travis for s3
update travis for s3

vladdu/rebar3,jbalint/rebar3,djnym/rebar3,rebar/rebar3,benoitc/rebar3,benoitc/rebar3,saleyn/rebar3,tsloughter/rebar3,erlang/rebar3,norton/rebar3,lrascao/rebar3,jbalint/rebar3,rebar/rebar3,project-fifo/rebar3,fauxsoup/rebar3,ferd/rebar3,fauxsoup/rebar3,project-fifo/rebar3