Prompt Users To Update Out Of Date Tools

[joefitzgerald]

A number of issues were resolved with gometalinter after the release of go-plus 4.0.0; but users were not aware of them or the need to update (i.e. go get -u github.com/alecthomas/gometalinter).

• [ ] Identify when a tool located by go-config is out of date
• [ ] Prompt a user to update the dependency
• [ ] Allow for a user to suppress the prompting
• [ ] Allow for a user to manually trigger the checking of dependency freshness

Out Of Scope For This Issue

• [ ] Display of status for all packages in GOPATH or vendor
• [ ] Mechanism to update all dependencies or specific dependencies in GOPATH or vendor

[lloiser]

Two packages that might be useful for this:

• https://github.com/divan/gofresh
• https://github.com/firstrow/go-outdated

[corvinusy]

Seems it will be good to provide an option to disable update-tools at all. Now Im forced to change local go-plus code to make this.