removed unused base attributes

ts/docx/xml-components/base-attributes.ts

@@ -1,17 +0,0 @@
-import {XmlComponent} from "./";
-
-export abstract class BaseAttributes extends XmlComponent {
-    private _attr: Object;
-
-    xmlKeys = {};
-
-    constructor(xmlKeys: Object, properties?: any) {
-        super("_attr");
-        this._attr = properties
-
-        if (!properties) {
-            this._attr = {};
-        }
-        this._attr["xmlKeys"] = this.xmlKeys;
-    }
-}