skip rubygems packaging rake tasks if Gem not defined
skip rubygems packaging rake tasks if Gem not defined

12spokes/rack-contrib,edmorley/rack-contrib,tobiashm/rack-contrib,edmorley/rack-contrib,tobiashm/rack-contrib,vivrass/rack-contrib,gferguson-gd/rack-contrib,vivrass/rack-contrib,gferguson-gd/rack-contrib