fixed: each key(repo) has only one recent commit's patch

Originally, I made mistake on upadte dictionary so it had only one
recent commit's patch per key(repo). So, I have fixed it.

Also, I have used list for value because dict does not have
sequence. However, the commit history has sequence. So, I have
used list for value instead of dict.

For example, you can see the following json format after you did run
the code.

{"/home/sanghee/PycharmProjects/repo/kreed/vanilla/.git":
    [
        ["03821bb", "changed lines...."],
        ["7c08cc6", "changed lines...."],
        ...
    ]
}

In this case, the first one in the list of value is the more recent one
than the second one. You can see the following for understanding.

$ pwd
/home/sanghee/PycharmProjects/repo/kreed/vanilla
$ git log --pretty=format:"%h %aD" -G ".setTag\([^,|^\(]*,[^,]*\)"
03821bb Thu, 11 Mar 2010 02:00:38 -0600
7c087cc Thu, 11 Mar 2010 01:04:30 -0600
568c5be Wed, 10 Mar 2010 23:04:49 -0600
fe5ff05 Wed, 10 Mar 2010 22:42:44 -0600
53ea3c4 Wed, 10 Mar 2010 00:32:15 -0600
1cc0081 Tue, 9 Mar 2010 23:08:06 -0600
958ffcc Mon, 8 Mar 2010 22:14:50 -0600