Fix UK Payroll unit tests

Author: SidneyAllen

src/test/java/com/xero/api/client/PayrollUkApiEmployeeTest.java

@@ -70,7 +70,8 @@ public void tearDown() {
     public void getEmployeesTest() throws IOException {
         System.out.println("@Test UK Payroll - getEmployeesTest");
 
-        Employees response =  payrollUkApi.getEmployees(accessToken, xeroTenantId, null, null,1);
+        String filter = "";
+        Employees response =  payrollUkApi.getEmployees(accessToken, xeroTenantId, filter,1);
 
         assertThat(response.getEmployees().get(0).getEmployeeID(), is(equalTo(UUID.fromString("aad6b292-7b94-408b-93f6-e489867e3fb0"))));
         assertThat(response.getEmployees().get(0).getFirstName(), is(equalTo("Jack")));

src/test/java/com/xero/api/client/PayrollUkApiTimesheetsTest.java

@@ -74,9 +74,8 @@ public void getTimesheetsTest() throws IOException {
         System.out.println("@Test UK Payroll - getTimesheetsTest");
 
         int page = 1;
-        UUID employeeId = UUID.fromString("cdfb8371-0b21-4b8a-8903-1024df6c391e"); 
-        UUID payrollCalendarId = UUID.fromString("cdfb8371-0b21-4b8a-8903-1024df6c391e"); 
-        Timesheets response = payrollUkApi.getTimesheets(accessToken, xeroTenantId, page, employeeId, payrollCalendarId);
+        String filter = "";
+        Timesheets response = payrollUkApi.getTimesheets(accessToken, xeroTenantId, page, filter);
 
         assertThat(response.getTimesheets().get(0).getTimesheetID(),is(equalTo(UUID.fromString("0c94d453-3d8c-4167-8c25-b4025121d18b"))));
         assertThat(response.getTimesheets().get(0).getPayrollCalendarID(),is(equalTo(UUID.fromString("216d80e6-af55-47b1-b718-9457c3f5d2fe"))));