Easy Go vendoring
git freeze will submodule or subtree all git-package Go imports from ./... into vendor/.
Status

Install
go get github.com/nicerobot/git-freeze
Usage
If your GOBIN is also in your PATH, git-freeze will be accessible as:
git freeze
Help
Usage:
-branch string
Git branch/commit to submodule/subtree. (defaults to the parent's branch)
-dry-run
Just print the command but do not run it.
-force
Force.
-list
Only list the imports that can be frozen.
-notests
Do not freeze test-imports.
-subtree
Use a subtree instead of a submodule.
-transitive
Traverse transitive imports, i.e. vendor/
-verbose
More output.
Note
git freeze -transitive will traverse ./..., so running it multiple times will continually freeze transitive dependencies. But, ideally, you do not want to use -transitive since transitive dependencies should be vendored/frozen by the package maintainer.