Make breadcrumbs fail nicely without department

Instead of crashing.
Only display ticks on y-axis of graph when showing data

To prevent case where whole-number graphs were shwoing [0, 0.5, 1] as y axis values, which is incongruous with integer values.
Merge pull request #506 from alphagov/bugfix/y-axis-ticks

Only display ticks on y-axis of graph when showing data
Add stub dashboard for Tier 2 Visit Visa
Make module ready event always be async

Need to make sure `Controller.renderModules` cannot callback before it has returned, so make all modules always be ready asynchronously, in particular when they don't have a collection so don't need to wait to fetch.
Return zero values fr completion when provided with zero input

Completion collection was incorrectly parsing 0 as "no data", which caused errors when datasets contain actual zero values.
Merge pull request #507 from alphagov/bugfix/completion-numbers-zero-values

Return zero values for completion when provided with zero input
Ensure denominatorMatcher and numeratorMatcher are always defined for completion collections

To avoid `d[this.matchingAttribute].match(this.denominatorMatcher)` (and similar) causing cross-browser issues with `.match(undefined)` returning inconsistent results.
Merge pull request #508 from alphagov/bugfix/completion-numbers-zero-values

Ensure denominatorMatcher and numeratorMatcher are always defined for completion collections
Move content dashboards out of /experimental/
Add slug to visitors and pageviews
Fixes from bug bash
Fix capitalization @alexmuller
Change dashboard-type to 'content' and published to 'true'
Move tagline out to a top-level property
Update cheapseats SHA
Merge pull request #489 from alphagov/tier-2-visit-visa

Tier 2 Visit Visa stub dashboard
Merge pull request #456 from pwaller/content-dashboards-live

Move content dashboards out of /experimental/
Add meta description for transaction pages.

This is for SEO purposes, in an effort to reduce the number of users who
click through to our transaction pages by mistake after entering generic
transaction-related search terms.

The meta description tries to make it clearer that this is a performance
dashboard with statistics - not the service itself.

Background here: https://www.pivotaltracker.com/s/projects/911874/stories/71237550
Add tests for meta description tag.