Remove unused files

src/api/article.js

src/api/qiniu.js

src/api/remoteSearch.js

src/router/modules/components.js

src/router/modules/table.js

src/views/components-demo/avatarUpload.vue

src/views/components-demo/backToTop.vue

src/views/components-demo/countTo.vue

src/views/components-demo/dndList.vue

src/views/components-demo/dragDialog.vue

src/views/components-demo/dragKanban.vue

src/views/components-demo/dragSelect.vue

src/views/components-demo/dropzone.vue

src/views/components-demo/jsonEditor.vue

src/views/components-demo/markdown.vue

src/views/components-demo/mixin.vue

src/views/components-demo/splitpane.vue

src/views/components-demo/sticky.vue

src/views/components-demo/tinymce.vue

src/views/example/components/ArticleDetail.vue