correct a typo

+PlotID/Publish.m

@@ -138,7 +138,7 @@ if ~configError %config File must exist
    configPath = PlotID.createFileCopy('config.json',folderName,...
        storPath,ID, 'data');
 else
-   configPath = fullpath(storPath,folderName, 'config.json');
+   configPath = fullfile(storPath,folderName,'config.json');
    config = struct(); 
    if ispc
     config.author = getenv('USERNAME');