Handle .gitignore

[ENAMINE1]

Inside the write_tree.cpp code we skip those entries which are a part of teh .gitignore file. But there can be a case when .gitignore dosent exits or the folder in which i am currently in dosent have the .gitignore file then in that case the code wont find any .gitnore file even if it exists in the outer parent directory.

• Handle the absence of .gitignore file
• Handlle the presence of .gitignore file in teh parent or grandparent directory somewhere.

|-- CMakeLists.txt
|-- Makefile
|-- cmake_install.cmake
|-- git_c
`-- src
    |-- CPP
    |   |-- cat_file.cpp
    |   |-- git_add.cpp
    |   |-- git_init.cpp
    |   |-- hash_object.cpp
    |   |-- ls_tree.cpp
    |   |-- main.cpp
    |   |-- utils.cpp
    |   `-- write_tree.cpp
    `-- Headers
        |-- cat_file.h
        |-- git_add.h
        |-- git_init.h
        |-- hash_object.h
        |-- ls_tree.h
        |-- utils.h
        `-- write_tree.h

Here there isnt any .gitignore file