rename close() to dismiss() and same goes for onClose prop

[Hamelatoire]

Enhancements suggested in this issue
#17

[Hamelatoire]

I can't seem to be able to add the hacktoberfest tag @ankurk91. It would be much appreciated if you could add it (and hacktoberfest-accepted if accepted)

[ankurk91]

Duplicate of
#39