Methods isActive(), getCurrentStep() and getHighlightedElement() now work
correctly (#13).
Using step events onShow and onHide no longer hides progress indicators
shown with progress = TRUE in $new() (#114).
Updated shepherd.js to 15.2.2.
conductor now scrolls smoothly between elements (#19).shepherd.js to v.10.0.1isCentered() is no longer supported because it was removed in
shepherd.js v.10.0.0.