[DRE-maint] Bug#1007770: Consider adding more key words as pre releases

[Pirate Praveen]

Package: gem2deb
Severity: wishlist

ruby-gollum-lib has
gitlab-gollum-rugged_adapter', '~> 0.4.4.4.gitlab.1'

in gemspec and 0.4.4.4.gitlab.1 is taken as 0.4.4.4~gitlab.1 for debian 
package version. But ruby:Depends does not convert .gitlab to ~gitlab.