update copy for overview page

@pbadenski
@abersager
Make wording fit mockups

- authorities page
- licences page
- single licence page
- single authority page

@abersager
@pbadenski
update column title for tables

@pbadenski
@abersager
use normalised model data for top 5 tables.

@pbadenski
@abersager
display links in top 5 tables on overview page.

@pbadenski
@abersager
Updated top 5 table column titles
Update line graph line styling
add links to licences and authorities pages to overview page
add govuk_frontend_toolkit dependency
style tweaks, add links to parent category

@edhorsford
@abersager
avoid scaling of tick and label lines
add basic responsiveness to applications graph

@edwardhorsford
@abersager
change top 5 tables on overview page from last month to last month
make navigation responsive
reduce page margin on small screens
Merge pull request #34 from alphagov/ui-tweaks

UI tweaks