Add slack notifications for Travis CI.
Add slack notifications for Travis CI.

IvyApp/ivy-codemirror,IvyApp/ivy-codemirror,mshafir/ivy-codemirror,HeroicEric/ivy-codemirror,mshafir/ivy-codemirror,HeroicEric/ivy-codemirror,HeroicEric/ivy-codemirror,mshafir/ivy-codemirror