chore(revert): Revert accidental change to showdown

Offending SHA: 0b6f1ce5f89f47f9302ff1e8cd8f4b92f837c413
chore(revert): accidental inclusion of nonexistent test.

Offending SHA: 0b6f1ce5f89f47f9302ff1e8cd8f4b92f837c413
fix(ngShow/ngHide): revert to display:'' for show

Regression introduced by ngAnimation
SHA: 0b6f1ce5f89f47f9302ff1e8cd8f4b92f837c413