Update README.md

Author: wkh237

README.md

@@ -40,6 +40,17 @@ Link package using [rnpm](https://github.com/rnpm/rnpm)
 rnpm link
 ```
 
+### version 0.7.0+ does not work with react-native 0.27 (Android)
+
+On 0.7.5, we have fixed Android OkHttp dependency issue on pre 0.28 projects excepted 0.27, 0.29.0, and 0.29.1. For 0.29.0 and 0.29.1 it's because `rnpm link` is broken in these versions, you may need to manually link Android package. It is recommended to upgrade you project if possible 
+
+```
+$ react-native upgrade
+```
+
+After the project upgraded, run `rnpm link` again.
+
+
 ### Manually link the package (Android)
 
 If rnpm link command failed to link the package automatically, you might try manually link the package.