Exclude Popper.js From BootstrapVue

Popper.js is automatically excluded if you don't import the relavant plugin.

If you import NavbarPlugin, Popper.js is imported because BNavItemDropdown uses it. You have to manually import each component used, rather than importing the entire plugin.

If you try to exlude Popper.js via webpack config, BootstrapVue will still complaint Popper.js is missing when a component who depends on Popper.js is imported.

{  externals: ['popper.js']}