Bug#950794: gem2deb should check if the shipped gemspec's version matches the package version

[Pirate Praveen]

Package: gem2deb
Version: 1.0.4
severity: wishlist

This was noticed in ruby-i18n which takes version of already installed 
package instead of the package we are building. So 1.5.3-1 shipped a 
gemspec with version 0.7 instead of 1.5.3. We should add a test to 
check if verison in changelog matches with the version in gemspec.