Added Fax Cover Page APIs

Added

• New Fax APIs:
  • GET /v2/phone/fax/cover_pages
  • GET /v2/accounts/{accountId}/phone/fax/cover_pages
  • GET /v2/phone/fax/cover_pages/download/{coverId}
  • GET /v2/accounts/{accountId}/phone/fax/cover_pages/download/{coverId}

Enhancements

• New cover_id,cover_note request fields in the following Fax APIs:
  • POST /v2/accounts/{accountId}/phone/fax/documents
  • POST /v2/phone/fax/documents