nGrinder git branching, version policy

Branching policy:

• Use git flow from 3.4.1

Version policy:

In ngrinder, there will be several kinds of version used:
X.0:
It should be significant upgrade and must follow the full developing process, with phase of alpha, beta. Like 3.0 version.
X.x:
It should be the version of some bug fix and function improvement. To release this version, we should follow the QA test and get QA's verification to release.
X.x.x
It will be some little bug fix, and will be release as soon as possible if only user posted some bugs. For this version, we will release it without QA's verification.