Support the using declaration from explicit resource management

Author: cowboyd

packages/eslint-plugin-prefer-let/lib/rules/prefer-let.js

@@ -76,7 +76,7 @@ module.exports = {
             message: 'prefer `let` over `var` to declare value bindings',
             node
           });
-        } else if (node.kind !== 'let' && !isTopLevelScope(node)) {
+        } else if (node.kind === 'const' && !isTopLevelScope(node)) {
           let constToken = sourceCode.getFirstToken(node);
 
           context.report({

packages/eslint-plugin-prefer-let/tests/lib/rules/prefer-let.js

@@ -118,6 +118,6 @@ ruleTester.run("prefer-let", rule, {
         message: "`const` declaration outside top-level scope",
         type: "VariableDeclaration"
       }]
-    }
+    },
   ]
 });