Deleted Jumbotron.vue component and fixed some bugs

Fixed the bug of upload avatar

Instead of the vue-resource by axios and fixed some bugs

Fixed some bugs

Fixed some bugs and add tests for articles api

Fixed some major problems and upgrade some packages

Instead of the vue-core-image-upload by cropper.js and improve the up…

…load feature

Fixed the problem for creating the tag and the category

Fixed the bug of the table's pagination

Add the config of the mail notification