Merge pull request #606 from DavidGamba/document-GoUpdateBinaries

Add documentation for GoUpdateBinaries in README

Author: fatih

README.md

@@ -63,7 +63,7 @@ Please be sure all necessary binaries are installed (such as `gocode`, `godef`,
 `:GoInstallBinaries` command. If invoked, all necessary binaries will be
 automatically downloaded and installed to your `$GOBIN` environment (if not set
 it will use `$GOPATH/bin`). Note that this command requires `git` for fetching the individual Go
-packages.
+packages. Additionally, use `:GoUpdateBinaries` to update the installed binaries.
 
 ### Optional