handle older versions of ubuntu

In Precise and newer, the name has been changed to protect the innocent.
This evaluates the logic in the recipe instead of the attributes for no
other reason than it might be clearer to the reader.
update to older version handling

Moved conditional to attributes, converted some arrays of words to Ruby
Wordlists, and updated some spacing.
Merge pull request #12 from DataDog/miketheman/git_pkg

handle older versions of ubuntu