Did I really Install GIT 2.0.1?
You probably now have two versions of git installed. If you type

which git


in the Terminal, it should tell you which one is in your PATH. For me, the above command returns

/usr/local/bin/git


The instructions you mention apparently install another copy of git here: /usr/local/git/bin/git

You need to add this new location to your PATH variable. To do so, navigate to your home directory and edit your .bash_profile by typing

cd
edit .bash_profile


and add the following line to it:

export PATH="/usr/local/git/bin:$PATH"


Save the file, open a new Terminal window and try typing git --version again. Hopefully, it should now run the newest version.