fix parameter name: it's product_id rigt now
adding upgrade product method to Connect::Client
add product_upgrade method for yast, update methods docs
fixes for rubocop
Merge branch 'master' into review_140527_upgrade_product_support

Conflicts:
	spec/connect/yast_spec.rb
point to yast code
yast url
fix typo
Merge pull request #85 from SUSE/review_140527_upgrade_product_support

[Review] Request from 'digitaltom' @ 'SUSE/connect/review_140527_upgrade_product_support'