Meeting Duration

[ane-gabriela]

Steps to reproduce:

1. Click on Create
2. Add a title for the new meeting
3. Click on Create

Expected results: After the start and end date are selected the Meeting Duration should be automatically shown.

Actual results: When creating a new meeting only the label of Meeting Duration appears. The duration itself appears after the page/meeting is saved.

Note: The app should either show the label and duration of the meeting or not show the meeting duration at all when first creating the meeting.