6.0.0

I'm extremely stupid and didn't commit as I go. To anyone reading this
I'm extremely sorry. A lot of these changes are very broad and I plan on
releasing Babel 6.0.0 today live on stage at Ember Camp London so I'm
afraid I couldn't wait. If you're ever in London I'll buy you a beer
(or assorted beverage!) to make up for it, also I'll kiss your feet and
give you a back massage, maybe.

packages/babel-plugin-transform-eval/src/index.js

@@ -3,13 +3,13 @@ export default function ({ parse, traverse }) {
     visitor: {
       CallExpression(path) {
         if (path.get("callee").isIdentifier({ name: "eval" }) && path.node.arguments.length === 1) {
-          var evaluate = path.get("arguments")[0].evaluate();
+          let evaluate = path.get("arguments")[0].evaluate();
           if (!evaluate.confident) return;
 
-          var code = evaluate.value;
+          let code = evaluate.value;
           if (typeof code !== "string") return;
 
-          var ast = parse(code);
+          let ast = parse(code);
           traverse.removeProperties(ast);
           return ast.program;
         }