Update README with the latest docker-app version

The WGET link under README seems to be broken. The release page is not captured under GITHUB repository. Hence, updating it to correct link.

Signed-off-by: Ajeet Raina <ajeetraina@gmail.com>

Author: ajeetraina

README.md

@@ -151,7 +151,7 @@ More examples are available in the [examples](examples) directory.
 Pre-built binaries are available on [GitHub releases](https://github.com/docker/app/releases) for Windows, Linux and macOS.
 
 ```bash
-wget https://github.com/docker/app/releases/download/0.1.0/docker-app-linux.tar.gz
+wget https://github.com/docker/app/releases/download/v0.2.0/docker-app-linux.tar.gz
 tar xf docker-app-linux.tar.gz
 cp docker-app-linux /usr/local/bin/docker-app
 ```