Changing Beta Indicator call to use new BetaLabel

Following on from https://github.com/alphagov/slimmer/pull/65. Only merge
once Slimmer has been updated and the  new version is in the Bundle.
Slimmer version bump with BetaLabelInserter

Now that https://github.com/alphagov/slimmer/pull/65 has been merged,
Contacts can display the BetaLabel properly
Restructure markup to remove empty beta div
Merge pull request #95 from alphagov/beta-label-change

Changing Beta Indicator call to use new BetaLabel