Upgrade gitlab-ui to v7.15.2
This MR upgrades GitLab UI to the current latest version which contains the following fixes:
7.15.2 (2019-11-20)
Bug Fixes
- alert: Explicitly set body line-height
- sparklines: Right align tooltip content
7.15.1 (2019-11-20)
Bug Fixes
- Use gitlab svg for closing icon of toasts
This version also comes with a new example for ~"component::infinite-scroll" (needed for !1627 (merged))
Edited by Paul Gascou-Vaillancourt