Adding required collection options for rendering graph axis.
Adding axis labels for live-service-usage (sparklines)
Lint fixes for visitors realtime collection
Added getDataByTableFormat for visitors-realtime.

Added required tests for this.

We may need to throttle the dataset but this should probably be done for graphs too up the stack.
Tables were rendering 'no data' for falsy values.

They don't do this anymore.

Added test to cover this.
Added new stub json for accessible tables in graphs.
Merge pull request #218 from alphagov/feature/no-realistic-dashboard-json-graph-table-updates

Json updates for accessible graphs on no-realistic-data requires feature/accessibleSparklines
Merge pull request #217 from alphagov/feature/accessibleSparklines

accessible sparklines requires feature/accessibleGraphsPartTwo