Ignore TryStatement's "handlers" property in favor of "handler"

[wbinnssmith]

I'm making this change because espree@2.x removes handlers entirely, so CatchClauses wouldn't be processed. Also, [estree has adopted handler in favor of handlers] https://github.com/eslint/eslint/issues/1930).

Esprima 2.1 and above (and pre-2.x espree) introduce handler while maintaining the old handlers array, so we can use it there too but must ignore handlers.

Flipping the ignore to the list, which would only have the one handler anyway, makes this all possible.