dep ensure Error#1-- go.uber.org/ratelimit in Gopkg.toml

[aure30]

How can I resolve the error below?

$ dep ensure
The following issues were found in Gopkg.toml:

  ✗ unable to deduce repository and source type for "go.uber.org/ratelimit": unable to read metadata: unable to fetch raw metadata: failed HTTP request to URL "http://go.uber.org/ratelimit?go-get=1": Get http://go.uber.org/ratelimit?go-get=1: dial tcp 216.58.223.83:80: connect: connection refused

ProjectRoot name validation failed