add base2.txt
add topic2-1.txt
 add master2.txt
add master3.txt
add master4
add rebase.txt
Merge pull request #4 from AtsukiTakahashi/topic2

add topic2-1.txt
add topic.txt
add topic_base2-1.txt
add pull-rebase
Merge pull request #5 from AtsukiTakahashi/topic_base

Topic base