append a new line to readme
 feature1
in the master
confilct fixed
try the no-ff option
 try the no-ff option in the master branch
 append a new line
merge with Fast Forward mod

enter a commit message to explain why this merge is necessary,
# especially if it merges an updated upstream into a topic branch.
#
# Lines starting with '#' will be ignored, and an empty message aborts
# the commit.
fix bug 001
 fix bug 001 and merge back to master
 create  a new file git.py
 add new file feature-1.py
merge feature-1