fix: Alias is uppercase

src/ua/UAAlias.ts

@@ -4,7 +4,7 @@ export class UAAlias implements IToXML{
                 public id: string) {
     }
     toXML(): XMLElem {
-        return new XMLElem('Alias', this.id).attr('alias', this.alias);  
+        return new XMLElem('Alias', this.id).attr('Alias', this.alias);  
     }
     static fromXML(xmlObject: any): UAAlias {
         return new UAAlias( xmlObject['@_Alias'], xmlObject['#text']);