Animate epic dates dropdowns opening like other dropdowns
Discussion
The following discussion from !3253 (merged) should be addressed (https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/3253#note_46726315):
5 Do you think it's possible to have the same dropdown animation as currently have for the issue “Due date” dropdown? (GIF)
It's possible but it's not trivial. I tried a few implementations with Vue and wasn't able to get very far. I'd like to put this off if we can, so that I can focus on the remaining portfolio management issues for 10.2
Outcome
Animate epic dates dropdowns opening like other dropdowns