Adds a "PRs" cell to the top of the page.
Omits "PRs" field if it's empty.
Fix api url typo [circle.com -> circleci.com]
Merge pull request #3237 from circleci/my-first-code-change

Adds a "PRs" cell to the top of the page.
Merge commit 'dca0a369135df09ef248e98107e704a6cb73b960'