Run `travis-ci` tests on `iojs` and `node` v0.12; speed up builds; allow 0.8/0.11/0.4 failures.
Run `travis-ci` tests on `iojs` and `node` v0.12; speed up builds; allow 0.8/0.11/0.4 failures.
ljharb/es7-shim,es-shims/es7-shim