update test

test/samples/duplicate-import-fails/_config.js

@@ -1,9 +1,12 @@
+var path = require( 'path' );
 var assert = require( 'assert' );
 
 module.exports = {
 	description: 'disallows duplicate imports',
 	error: function ( err ) {
-		assert.ok( false ); // TK - pick an error message
+		assert.equal( err.file, path.resolve( __dirname, 'main.js' ) );
+		assert.deepEqual( err.loc, { line: 2, column: 9 });
+		assert.ok( /Duplicated import/.test( err.message ) );
 	}
 };