Make Ruby / Rubygems-Version in postinstall.sh for Ubuntu more DRY

[ctrabold]

Hi Patrick,

I introduced two new shell for the Ruby / Rubygems-Version which speeds up the process of these two (=Timesaver).

Tested by calling "postinstall.sh" directly - worked as expected, no errors.

Cheers

Christian

[hedgehog]

@ctrabold, I'm not sure this is the env variable needed going forward. If you review the postinstall.sh in this pull request
you'll see that what is needed is more finegrained. Also I think VEEWEE_* in this case is too specific and we should use more generic names. the reason for this is I think the way to structure the scripts is to replace postinstall.sh with
veewee_pre.sh, generic.sh, veewee_post.sh. That is, the veewee definition file 'definition.rb` should contain:

  <snip>
 :postinstall_files    => [ 'veewee_pre.sh', 'generic.sh', 'veewee_post.sh' ],

Your thoughts?

[ctrabold]

Good point. After reading your pull request, I totally agree.

My point in introducing the env variables was simple to make changing the versions of ruby / rubygems more fun ;)

I'll close this pull request.