Update eslint-config-babel to the latest version 🚀 (#273)

* chore(package): update eslint-config-babel to version 4.0.0

https://greenkeeper.io/

* Fix prefer-const

* Update package.json

src/util/location.js

@@ -26,7 +26,7 @@ export class SourceLocation {
 export function getLineInfo(input, offset) {
   for (let line = 1, cur = 0; ;) {
     lineBreakG.lastIndex = cur;
-    let match = lineBreakG.exec(input);
+    const match = lineBreakG.exec(input);
     if (match && match.index < offset) {
       ++line;
       cur = match.index + match[0].length;