Add browse page for environmental management

Part of https://www.pivotaltracker.com/s/projects/1010882/stories/68145052
Merge pull request #546 from alphagov/add-environmental-management

Add browse page for environmental management
Add 'Environment and countryside' link to homepage
Merge pull request #547 from alphagov/environment-browse-category

Add 'Environment and countryside' link to homepage
Replace media-player styles

Replace styles with @MarkHurrel's redesign from alphagov/whitehall
Remove old media player images

These are no longer used following the redesign in 6e99bcf6
Remove media-player assets

As the media player is shared across apps it now lives in static
Remove media player references

The CSS & javascript are now in the static application files & no longer need adding to templates manually
Use video styles from toolkit

- Re-add the media-player-loader JavaScript. Initalization should live
  with each app customised for the app
- Bump the toolkit so the video Sass files are available
- Use the video player sass files
Merge pull request #418 from alphagov/marks-media-player

Remove media player
Add running a charity specialist sector

Part of https://www.pivotaltracker.com/story/show/67287568
Counterpart to https://github.com/alphagov/panopticon/pull/148
Merge pull request #549 from alphagov/add-running-a-charity-specialist-sector

Add running a charity specialist sector
Add Competition SpecialistSector

Part of https://www.pivotaltracker.com/story/show/67991848 and counterpart
to https://github.com/alphagov/panopticon/pull/147
Merge pull request #548 from alphagov/add-competition-specialist-sector

Add Competition SpecialistSector
create exceptional start page for view driving licence
Create new driving record page

Added as exception to root controller
modified beta styles to tax disc scss as it was used for both pages
created new scss file
test
changed tests based on merge