Roger's suggested changes to PR template

These are ideas Roger had for the template. I'll let him elaborate but I think the gist of it is that more people are checking against the Jira, and ensuring we're not blocked waiting for IPs to complete code review before merging.
I agree with Ollie, if it's explicitly stated that a PR can be merged without an IP then there's no real push for them to concern themselves with looking at the PRs and so they won't learn from reviewing other people's code.