fix(popover): arrow positioning issues

[fbasso]

fix #2089

[fbasso]

By the way, this PR will fix #2234, regarding the arrow positioning. The remaining fix must be done with container="body", as popover in popover is not supported with Bootstrap.

[maxokorokov]

LGTM, thanks!

Will merge when Travis is green

[codecov-io]

Codecov Report

Merging #3006 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #3006   +/-   ##
=======================================
  Coverage   92.38%   92.38%           
=======================================
  Files          91       91           
  Lines        2822     2822           
  Branches      451      451           
=======================================
  Hits         2607     2607           
  Misses        162      162           
  Partials       53       53

Flag	Coverage Δ
#e2e	60.63% <ø> (ø)	⬆️
#unit	90.88% <ø> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 64d5716...79e9753. Read the comment docs.