Bump binding_of_caller from 0.7.3 to 0.8.0
Bump binding_of_caller from 0.7.3 to 0.8.0

Bumps [binding_of_caller](https://github.com/banister/binding_of_caller) from 0.7.3 to 0.8.0.
- [Changelog](https://github.com/banister/binding_of_caller/blob/master/HISTORY)
- [Commits](https://github.com/banister/binding_of_caller/compare/v0.7.3...v0.8.0)
alphagov/frontend,alphagov/frontend,alphagov/frontend,alphagov/frontend