v4: Fix outdated utilites classes

Convert Collapse accordion from Panels to Cards

Updated Download docs

[Fix #17611][V4] Change destroy to dispose for tooltip in _JQueryInterface

Strip $ from copied shell commands.

[Fix #17555][V4] fix resetting style on closing collapse

Fix Travis errors due to npm/npm#14042.

Set height on custom select

Matches the changes from #20874 to the regular select element. This is really only necessary for IE and Edge near as I can tell. Fixes #20810.

Match the height of select.form-control with input.form-control

Uses a local variable and some calc love to counteract the border-width (times 2) from the height of the select. Fixes #17194 and nullifies #19967.

Update dependencies, including Babel to v6 and zeroUnits fix.

Reset the left and right border on list items for flush list groups

Avoid the resetting of the already set values in #20397. Fixes #20395.

Update devDependencies badge link.

Form validation fixes