Fixed issue 167

[pierreericgarcia]

Issue 167

This pull request attend to fix the issue 167.

The subject of the issue was the non-functionality of the Top Navigation elements. When we clicked on the Steps, the app where returning us undefined and we were not changing the current step.

The bug was there because when we clicked on Steps, it was not the <li/> elements that were trigger (the element where the jumpToStep function is called but it was its children (<em/> and <span/>).

In order to fix this I've added an inline style property pointer-events: none; to each of the children of the <li/> element.

This way when we click on the <Step/> it's always the <li/> element which is trigger, so the jumpToStep is called and StepZilla works correctly.