use Ruby 2.1.0 at Travis

SLE12 has been switched to Ruby 2.1
Revert "Allow failed download of eula for betas"

This reverts commit 19939a8d2a165a34e034f09dab42b105cf7a4d2f.

Conflicts:
	src/lib/registration/ui/addon_eula_dialog.rb
Merge pull request #117 from yast/ruby_2.1

use Ruby 2.1.0 at Travis
changes

- 3.1.79
Merge pull request #118 from yast/remove_eula_download_workaround

Remove EULA download workaround
add snippet example for autoyast
smaller heading
Merge pull request #119 from yast/ay_snippet

Ay snippet
cleanup
do not register the base product again when going back at update
display full product name when updating base product registration
update addons/extensions

(matching the product name)