Remove collections package

It doesn't needed anymore аfter port and ip allocators refactoring
Docker-DCO-1.1-Signed-off-by: Alexandr Morozov <lk4dmath@gmail.com> (github: LK4D4)
Fixes #5749
libcontainer support for arbitrary route table entries

Docker-DCO-1.1-Signed-off-by: William Thurston <me@williamthurston.com> (github: jhspaybar)
Merge pull request #5868 from jhspaybar/5749-libcontainerroutes

libcontainer support for arbitrary route table entries
Merge pull request #6076 from LK4D4/remove_collections_package

Remove collections package