only pluralize PRs when there are multiple (on build page)
Add "Courier New" to monospace font stack.

Fixes #1709
Merge pull request #3303 from circleci/prs-pr

Only pluralize PRs when there are multiple (on build page)
Merge commit 'cbdb45a2ada043dea9d38a25c25f5247a8880023'
Merge commit 'cf67366238e94195f2d58aeab85ba78f055c4bc3'