Fix customer satisfaction delta position and size

- Use core-24 font mixin for font size
- Reduce the left position on small screens
Fetch collection after creating the view

This should fix the rendering of the customer satisfaction module on
IE7. It seems to be caused by some weird race condition, only on IE; more
investigation needed on this.
Merge pull request #184 from alphagov/fix-customer-satisfaction-ie

Fix customer satisfaction module on IE 7
Fix customer satisfaction responsiveness

Fixed vertical alignment of previous number on small screens
and positioning of arrow on intermediate screen sizes.
Merge pull request #183 from alphagov/fix-customer-satisfaction-delta

Fix customer satisfaction delta position and size
Merge branch 'master' into add_evl_digital_uptake_module
Let time based graphs observe period of query object
Switch digital takeup collection to monthly data

Now using improved collect:sum query. Developed against stub so might require further tweaks.
Add date period formatting method to base View
Switch date formatting for digital takeup number view
Fix feature tests
Minor refactor