Now we are developing 3.1 version, and maintaining 3.0 version at the same time. So we need brabching for them. And the branching policy will be as below:
- We will work on master for 3.1 version, and create a branch for 3.0 version.
- And if only we fix some bug and release, we will merge this into master.

- For 3.0 maintaining, according to the importance and difficulty, we will release a patch version in 1~4 days.