(maint) Move versionbump into utils
Add test for Pkg::Util::Version.versionbump
(maint) Fix version burn in

Previously the versionbump task would fail because workspace is not defined in
the tar task. It is defined in tar.rb, so this commit updates the tar library
to do the version burn in if the setting is set.
(maint) Add pry to gemset for debugging purposes
(maint) Add .gitignore entry for .bundle directory
(maint) Add a minimal versionbump task to maintain backward compatibility.
Merge pull request #276 from haus/maint/master/fix_version_burn_in

(maint) Fix version burn in