Companies House site config

It's my first new config. Is this right?
Merge pull request #1023 from rjc123/newsites

Change DECC restats configuration information
Merge pull request #1022 from adammaddison/master

Companies House site config
Pin the version of Webmock

This is good practice, but I also want to check that the CI build pushes to the
release branch.
Merge pull request #1024 from rjc123/newsites

Revise homepage for restats. Again.
Update TNA timestamp for hs2