Root project uses dep as dependency management, Gopkg.lock need to be present in root directory.
Every dependency is licensed under one license known to this tool.
All dependencies need to be in the vendor folder including their LICENSE files.
Known limitations
Skips dependencies without license, either because they don't have one or it is absent in vendor folder.
Skips dependencies which bury the license file in a non-standard location, e.g. by embedding it in README.
Sometimes does not work for dependencies with heavy re-formatting of the LICENSE file, e.g. by using markdown, prefixing every line wth "> ", etc.
Line breaks and spaces are OK though.
A quick test showed this tool to work on ~50% of the projects in my GOPATH.