Consistent usage of moment add and subtract

In later versions they’ve deprecated the signature (period, number) so
following that guidance.
Upgrade moment dependencies

These showed up as sufficiently slow when profiling that I was
concerned. This is probably the headline change.

https://github.com/moment/moment-timezone/commit/803d2e2e936acf79b709ee5b5bb584cccd58e460
Allow overriding of flatten.

Flatten is currently problematic for some modules when
backdrop has to fill in lots of empty permutations. In
this case we should be able to turn flatten off.
Merge pull request #850 from alphagov/performance

Various nudges to improve HTML response times
Fix bug in flat data for completion_rate module

This completion_rate does not support the case where multiple pieces
of data are used in the compilation of a single data point representing
a given time period.

Additionally, this module would sometimes result in duplicated output
in the table that accompanies a graph, for example on 'SORN':

    1 to 30 November 2013                    123%
    1 to 30 November 2013                    123%
Merge pull request #851 from alphagov/flatten-override

Allow overriding of flatten.
Merge pull request #852 from alphagov/bugfix-completion-rate-flat-data

Fix bug in flat data for completion_rate module
Use the column module and just extend from that.
Only display the label for days if it's an integer.
Add valueAttr to the application module
first-of-type is hateful.
If we want multiple rows of cols3 we're going to need to add a first so we can clear the margin.
It would work if we had more nesting but meh.
Headline figure view.

Server side view that uses a percentage volumetric.

This is just an extension of the target view but modified to just show percentages of achieved targets.
Updated rendering for headline-figure