I'm getting this error while i'm running my test class. I have a webservice class which will send sms when i insert a new record or if i update a an existing record

Here are my webservice class, trigger which is invoking webservice call and test class for both class & trigger.

Web Service call

public class CreatingAccountsendsms { 
@Future(callout=true)
    public static void Creating_Lead(string mobile,string leadname,string Uname,string UMobilePhone) {
    
   // list<account> acc=[SELECT Id,Phone FROM Account where id=:conId];
    
                  String Username ='management@abc.com';
                  String Password = '321@admin';
                  String TempID='21341';
                  String MobileNo=mobile;
                  String SenderID = 'ABC';
                  String F1= leadname;
                  String F3= Uname;
                  String F2= UMobilePhone;
                  String F4= '';
       String postData = 'username=' +Username + '&pass=' + Password + '&dest_mobileno=' + MobileNo +'&senderid=' + SenderID + '&tempid=' + TempID+'&F1=' + F1+ '&F2=' + F2+ '&F3=' + F3+'&F4=' + F4;
       
       HttpRequest req = new HttpRequest();
    req.setEndpoint('http://123.01.01.01/blank/sms/user/urlsmstemp.php?'+postdata);
    req.setMethod('GET');
    system.debug(req);
    Http h = new Http();
    HttpResponse res = h.send(req);
    
    //system.debug(res);
    //return res;
    } 

     @Future(callout=true)
    public static void CreatingAccountsendsms1(string mobile,string leadname,string Uname,string UMobilePhone) {
   
   // list<account> acc=[SELECT Id,Phone FROM Account where id=:conId];
   
                  String Username ='management@ABC.com';
                  String Password = '321@admin';
                  String TempID='21342';
                  String MobileNo=mobile;
                  String SenderID = 'ABC';
                  String F1= leadname;
                  String F2= Uname;
                  String F3= UMobilePhone;
                  String F4= 'creatorname';
       String postData = 'username=' +Username + '&pass=' + Password + '&dest_mobileno=' + MobileNo +'&senderid=' + SenderID + '&tempid=' + TempID+'&F1=' + F1+ '&F2=' + F2+ '&F3=' + F3+'&F4=' + F4;
      
       HttpRequest req = new HttpRequest();
    req.setEndpoint('http://123.01.01.01/blank/sms/user/urlsmstemp.php?'+postdata);
    req.setMethod('GET');
    system.debug(req);
    Http h = new Http();
    HttpResponse res = h.send(req);
   
    //system.debug(res);
    //return res;
    }

}

Trigger to invoke my webservice method

trigger sms on Account (after insert,after update) {


for(Account acc:trigger.new)
{
user u=[SELECT Alias,Id,MobilePhone,Name,Phone,ProfileId FROM User where Id=:acc.OwnerId];
Profile p = [SELECT id,Name FROM Profile WHERE Id = :u.profileid];
system.debug('@@@@@@@@@+++++++++++++++++++++++++++++++++++++++++++++++++++++='+p.name);


if(trigger.isafter){
 CreatingAccountsendsms.Creating_Lead(acc.PersonMobilePhone,acc.Lastname,u.name,u.phone);
}
if(trigger.isupdate)
{
user u1=[SELECT Alias,Id,MobilePhone,Name,Phone FROM User where Id=:acc.CreatedById];
if(acc.ownerid != trigger.oldmap.get(acc.id).ownerid )
{
if(p.name=='SPU - Sales Manager' || p.name=='Unishire Sales Profile' || p.name=='Channel Sales Manager')
{
system.debug('@@@@@@@@@+++++++++++++++++++++++++++++++++++++++++++++++++++++='+p.name);
 sendsms.sendsms1(u.MobilePhone,u.name,acc.Lastname,acc.PersonMobilePhone,acc.Project_Interested__c,u1.name);
 CreatingAccountsendsms.CreatingAccountsendsms1(acc.PersonMobilePhone,acc.Lastname,u.name,u.MobilePhone);
 //acc.name=u.Lastname;
//sendsms.sendsms1(acc.Phone1__c,acc.name);
}
}
}
}
}

the above class and trigeer is for Account object and I have same kind of class and trigger for Debit Note also. 

In my test class if i just insert account test method will be passed if i insert new debit note record along with account then i'm getting this callout exception

Error Message : System.CalloutException: You have uncommitted work pending. Please commit or rollback before calling out
Stack Trace  :  Class.CreatingAccountsendsms.Creating_Lead: line 50, column 1

Here is my test class

@isTest(SeeAllData=true)
public class new_test_class1{
    @isTest static void Test_lead(){
        
        Account acc= new Account(); 
        acc.name='Acc1';
        acc.Status__c='new';
        acc.Custom_AN__c=1;
        acc.Project_Interested__c='atrium';
        acc.Phone1__c='8015825819';
        acc.Email__c='samdbinu@gmail.com';
        insert acc;
        
        Debit_Note__c DN = new Debit_Note__c();
        DN.Name = 'test';
        DN.Account__c = acc.id;
        insert DN;
        
        
                
        Test.startTest();
         Test.setMock(HttpCalloutMock.class, new Stubby());
         string mobile = '12345';
         string name = 'Sharat';
         string status = 'done';
         string dateon = '1/1/2014';
         string Uname = 'New';
         string Umobile = '90086573';
         string leadname = 'Test';
         string UMobilePhone = '90087345';
        
         CreatingAccountsendsms.CreatingAccountsendsms1(mobile,leadname,Uname,UMobilePhone);
        Test.StopTest();
    }
}