v1.1-appid keep retrofit 1.x and update all other libraries to latest version. And apply appid from http:openweathermap.org to resolve api response with 401 error code.
[v2.0] upgrade retrofit to 2.x, companied with okhttp3 and its logging-interceptor
[v2.1] move common request parameters, appid, from each api to isolate networking interceptor
[v2.2] apply rxjava adapter and request api in rx ways
[ui-2.x] branch off from v2.2 and improve ui functions via integrating libraries
[di-aspect-2.x] experience with AspectJ for components seperation. e.g., as openweathermap could not response city name with Chinese, we could extend the query by Hanzi2Pinyin，before emitting query.
[realm-2.x] experience with local database framework, realm
[data-repository-2.x] deploy repository pattern for data layer query, union both remote retrofit request and local realm database for weather query.
[cache-2.x] cache data, branch off from tag v2.0