Issue 1067 in include-what-you-use: fix includes.py not removing suggested includes

[notifi...@include-what-you-use.org]

New issue 1067 by pshrey795: fix_includes.py not removing suggested includes
https://github.com/include-what-you-use/include-what-you-use/issues/1067

Using the following source files and their corresponding headers:

**A.h**
`#include <vector>
#include <string>

class A{
public:
int a_one;
int a_two;

A();
void setZero();
};`

**A.cpp**
`#include "A.h"

A::A(){
a_one = 1;
a_two = 2;
}

void A::setZero(){
a_one = 0;
a_two = 0;
}`

**B.h**
`#include "A.h"
using namespace std;

class B{
private:
A* b_one;
int b_two;
vector<int> b_three;

public:
B();
void setZero();
int getMem(){
return b_one->a_one;
}
};`

**B.cpp**
`#include "B.h"

B::B(){
b_two = 2;
b_one = new A();
}

void B::setZero(){
b_two = 0;
b_one->setZero();
}

int main(){
}`

**C.h**
`#include "B.h"
using namespace std;

class C{
private:
B* c_one;
int c_two;
string c_three;

public:
C();
void setZero();
};`

**C.cpp**
`#include "C.h"

C::C(){
c_two = 2;
c_one = new B();
c_three = "hello";
}

void C::setZero(){
c_two = 0;
c_three = "";
c_one->setZero();
}`

I built these source files together and ran iwyu on them using CMake. The corresponding suggestion that I am getting in the file iwyu.out are:
`Warning: include-what-you-use reported diagnostics:

A.h should add these lines:

A.h should remove these lines:
- #include <string> // lines 2-2
- #include <vector> // lines 1-1

The full include-list for A.h:
---

(A.cpp has correct #includes/fwd-decls)

Warning: include-what-you-use reported diagnostics:

B.h should add these lines:
#include <iosfwd> // for std
#include <vector> // for vector

B.h should remove these lines:

The full include-list for B.h:
#include <iosfwd> // for std
#include <vector> // for vector
#include "A.h" // for A
---

(B.cpp has correct #includes/fwd-decls)

Warning: include-what-you-use reported diagnostics:

C.h should add these lines:
#include <iosfwd> // for std
#include <string> // for string
class B;

C.h should remove these lines:
- #include "B.h" // lines 1-1

The full include-list for C.h:
#include <iosfwd> // for std
#include <string> // for string
class B;
---

C.cpp should add these lines:
#include "B.h" // for B

C.cpp should remove these lines:

The full include-list for C.cpp:
#include "C.h"
#include "B.h" // for B
---
`

This is exactly what I expect to be correct. But the python script fix_includes.py is not removing the includes which are suggested above. It only adds the includes which are suggested to be inserted. Please check this. I will greatly appreciate it.