dillon1000/react

Upgrade to newer eslint, use esprima-fb

Eslint now allows us to use a different parser, which allows us to use
esprima-fb explicitly. This means we don't have to wait for espree to add
things like rest-param parsing. Though we do need eslint to upgrade its rules
to handle that AST.

I had hoped to enable parsing of our tests but we can't do that until we
change esprima-fb's XJS nodes to JSX.

While I was here, I also enabled the no-unused-vars rule since eslint
understands template strings. I also made the single quote enforcement
actually fail instead of just warn.