Updated simple manifest for localhost

Manifest.xml

<?xml version="1.0" encoding="UTF-8"?>
<OfficeApp
          xmlns="http://schemas.microsoft.com/office/appforoffice/1.1"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xmlns:bt="http://schemas.microsoft.com/office/officeappbasictypes/1.0"
          xmlns:ov="http://schemas.microsoft.com/office/taskpaneappversionoverrides"
          xsi:type="TaskPaneApp">
  <Id>5226365f-62d0-435f-a4af-cc6a7bd753b2</Id>
  <Version>1.0.0.1</Version>
  <ProviderName>TheOfficeContext.com</ProviderName>
  <DefaultLocale>en-US</DefaultLocale>
  <DisplayName DefaultValue="BasicAddin" />
  <Description DefaultValue="This is a basic addin."/>
  <IconUrl DefaultValue="http://127.0.0.1:8080/default.png" />
  <Hosts>
    <Host Name="Workbook" />
  </Hosts>
  <DefaultSettings>
    <SourceLocation DefaultValue="http://127.0.0.1:8080/home.html" />
  </DefaultSettings>
  <Permissions>ReadWriteDocument</Permissions>
</OfficeApp>