.travis.yml used single quotes which is inconsistent with what we use in most
other files. Also, the file was missing an empty line at the end.
(cherry-picked from 06320c88af)
Node.js & io.js have merged, there will be no more major io.js releases.
Also, as of today io.js is officially unsupported (even if it still gets some
updates) while Node.js 4.0.0 (just released!) will be supported until 2018.
(cherry-picked from 250a1990ba)