Since our Bootstrap beta 2 release, we added two new dist files : bootstrap.bundle.js
and bootstrap.bundle.min.js
which contain Popper.js
inside
Plus use this link to find the latest release of Popper.js : https://cdnjs.com/libraries/popper.js because the above linked release (1.8.2) is very old, latest is 1.12.9
BTW you should choose the UMD release of Popper.js because it’s the one used by Bootstrap