AMD: Support files with embedded es6

Fixes pahen#84

package.json

@@ -24,7 +24,7 @@
     "test": "./node_modules/.bin/grunt"
   },
   "dependencies": {
-    "amdetective": "0.0.2",
+    "amdetective": "0.2.1",
     "coffee-script": "1.3.3",
     "colors": "^1.1.2",
     "commander": "^2.8.1",

test/amd.js

@@ -118,4 +118,10 @@ describe('module format (AMD)', function () {
 			findNestedDependencies: true
 		}).obj().should.eql({ 'main': ['a', 'b'] });
 	});
+
+	it('should work for amd files with es6 code inside', function () {
+		madge([__dirname + '/files/amd/amdes6.js'], {
+			format: 'amd'
+		}).obj().should.eql({ 'amdes6': ['ok/a'] });
+	});
 });

test/files/amd/amdes6.js

@@ -0,0 +1,13 @@
+define([
+  'ok/a'
+], function(a) {
+  'use strict';
+
+  var x = [1, 2, 3, 4]
+
+  for (var i of x) {
+    x++;
+  }
+
+  return x;
+});