Update cmd/goimports link.

Related to #328.

README.md

@@ -734,7 +734,7 @@ Go software and plugins.
 * [Go Metalinter](https://github.com/alecthomas/gometalinter) - Metalinter is a tool to automatically apply all static analysis tool and report their output in normalized form.
 * [goast-viewer](https://github.com/yuroyoro/goast-viewer) - Web based Golang AST visualizer.
 * [GoCover.io](http://gocover.io/) - GoCover.io offers the code coverage of any golang package as a service.
-* [goimports](http://godoc.org/code.google.com/p/go.tools/cmd/goimports) - Tool to fix (add, remove) your Go imports automatically.
+* [goimports](https://godoc.org/golang.org/x/tools/cmd/goimports) - Tool to fix (add, remove) your Go imports automatically.
 * [GoLint](https://github.com/golang/lint) - Golint is a linter for Go source code.
 * [Golint online](http://go-lint.appspot.com/) - Lints online Go source files on GitHub, Bitbucket and Google Project Hosting using the golint package.
 * [validate](https://github.com/mccoyst/validate) - Automatically validates struct fields with tags.