fix(Dropdown): more logic for clearing search

[lottamus]

Fixes #1952.

• fix(Dropdown): clear search if adding item or if selection is only option Multi-select Dropdown does not clear value after "onAddItem" #1952
• test(Dropdown): add test for clear search if selection is only option

[levithomason]

Heads up, tests are failing due to lint:

/home/ubuntu/Semantic-UI-React/src/modules/Dropdown/Dropdown.js
  599:53  error  Extra semicolon  semi
  603:64  error  Extra semicolon  semi
  702:64  error  Extra semicolon  semi
  711:53  error  Extra semicolon  semi

You can run npm run lint:fix to fix most errors and then push. Note that you can ignore warnings.

[codecov-io]

Codecov Report

Merging #1956 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff            @@
##           master   #1956      +/-   ##
=========================================
+ Coverage    99.8%   99.8%   +<.01%     
=========================================
  Files         148     148              
  Lines        2568    2573       +5     
=========================================
+ Hits         2563    2568       +5     
  Misses          5       5

Impacted Files	Coverage Δ
src/modules/Dropdown/Dropdown.js	100% <100%> (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 a4780cd...6eb1456. Read the comment docs.

[rijk]

Awesome this will be fixed + the extra tests. Great work @ChrisNLott , hope it will be merged soon, this is really bugging us in production as well.

[levithomason]

Thanks much @ChrisNLott. I'll make a release today.

[levithomason]

Released in [email protected]