rubylibs: add several expressions

* `celluloid`
* `coderay`
* `colorator`
* `excon`
* `fast_steamer`
* `formatador`
* `guard`
* `jekyll`
* `listen`
* `lumberjack`
* `posix_spawn`
* `rb_kqueue`
* `rest_client`
* `rmagick`
* `syntax`
* `launchy`
* `pry`
* `rubyzip`