###User stories:
As an event organizer, I want to be able to set a goal for my event, so that participants are motivated to join and contribute based on the goal, and so that I can have a clear story of the event outcome based on the goal.
As an event participant, I want to know how my contributions help accomplish the goals of the event, so that I can understand the impact of my edits and of the event overall.
###Acceptance Criteria:
* Given that an event has a goal set,
** A progress bar should be displayed in the Contributions tab for EventDetails
* And if contributions related to the goal have been made,
** The progress bar should be updated to display the change against the goal
* And if contributions related to the goal have not been made,
** The progress bar should still display, but it should not be shaded in at all
* And if the goal has been met,
** There should be text next to the %, so that it reads as: "Goal exceeded by [X]%"
*** And X is the percentage exceeded (for example, 110%)
###Visual example:
| Progress against goal in Contributions tab| {F68031727}