implement ApiClient on MyVehicle_VehicleAdapter;
remove the usage of GetRequest and its subscribes on MyVehicle_VehicleAdapter;
update getApiClient();
add signin() to ApiInterface;
implement ApiClient.getApiClient() on UserAuth;
add ACCESS_NETORK_STATE permission to manifest;
remove the usage of GetRequest and its subscribes on UserAuth;
add @FormUrlEncoded annotation to resolve the "Only one HTTP method is allowed. Found: POST and POST" error listed on https://github.com/square/retrofit/issues/560;
code clean up, no code changes;
reenable toast message;
specify the REST call to be json type;
add createUser() to ApiInterface;