Add buildbot 0.9 support in README.md

Author: coldnight

README.md

@@ -96,7 +96,7 @@ pip install -e homu
 
 4. Add a Webhook to your continuous integration service:
 
- - Buildbot
+ - Buildbot 0.8
 
    Insert the following code to the `master.cfg` file:
 
@@ -109,6 +109,39 @@ pip install -e homu
     ))
     ```
 
+  - Buildbot 0.9 via GithubStatusPush
+
+    Buildbot 0.9 support [GithubStatusPush](http://docs.buildbot.net/latest/manual/cfg-reporters.html#githubstatuspush),
+    so we can use this to integrate with Github and Buildbot 0.9.
+
+    Insert the following code to the `master.cfg` file:
+
+    ```python
+    from buildbot.plugins import reporters, util
+    from buildbot.process.properties import Interpolate
+
+
+    context = Interpolate("buildbot/%(prop:buildername)s")
+    gs = reporters.GitHubStatusPush(token='A Github personal acess token',
+                                    context=context,
+                                    startDescription='Build started.',
+                                    endDescription='Build done.')
+    c['services'].append(gs)
+    ```
+
+    **Note**: Buildbot 0.9 use project to detect the repository at Github. So made your `project` to `<owner>/<repo>` 
+    in [GitPoller](http://docs.buildbot.net/latest/manual/cfg-changesources.html#gitpoller).
+
+    Now the config of the repository in Homu's config file should looks like below:
+
+    ```toml
+    [repo.NAME.status.LABEL1]
+    context = "buildbot/<builder-name>"     # <builder-name> should replaced by the real builder name
+
+    [repo.NAME.status.LABEL2]
+    context = "buildbot/<builder2-name>"     # <builder2-name> should replaced by the real builder name
+    ```
+
  - Travis CI
 
    Add [your Travis token][travis] as `repo.NAME.travis.token` in cfg.toml.