README: Switch to travis-ci.com for badge (#709)

README.md

@@ -128,8 +128,8 @@ pinned in zap's [glide.lock][] file. [↩](#anchor-versions)
 
 [doc-img]: https://godoc.org/go.uber.org/zap?status.svg
 [doc]: https://godoc.org/go.uber.org/zap
-[ci-img]: https://travis-ci.org/uber-go/zap.svg?branch=master
-[ci]: https://travis-ci.org/uber-go/zap
+[ci-img]: https://travis-ci.com/uber-go/zap.svg?branch=master
+[ci]: https://travis-ci.com/uber-go/zap
 [cov-img]: https://codecov.io/gh/uber-go/zap/branch/master/graph/badge.svg
 [cov]: https://codecov.io/gh/uber-go/zap
 [benchmarking suite]: https://github.com/uber-go/zap/tree/master/benchmarks