Change Sign in and Sign out paths
Change Sign in and Sign out paths

A part of the work to broaden the transition checker login prototype to
the whole of GOV.UK. As outlined in [RFC#134][1] we are moving sign in
and sign out paths from being nested in finder-frontend (which would be
strange for a GOV.UK-wide login!) onto their own paths.

See the RFC for more detail on these two paths:
- [Sign in][2]
- [Sign out][3]

[1]: https://github.com/alphagov/govuk-rfcs/pull/134
[2]: https://github.com/alphagov/govuk-rfcs/pull/134/files#diff-f5a6037308ea735f2a6e63b3080e78792499608bcad7386a49cf94799634d1beR224
[3]: https://github.com/alphagov/govuk-rfcs/pull/134/files#diff-f5a6037308ea735f2a6e63b3080e78792499608bcad7386a49cf94799634d1beR243

alphagov/static,alphagov/static,alphagov/static