Download link in readme is broken

[amarouni]

Description

The download link : https://github.com/docker/app/releases/download/v0.1.0/docker-app-linux.tar.gz refers to the old release and is broken

Steps to reproduce the issue:

1. Refer to installation section

Describe the results you received:

wget https://github.com/docker/app/releases/download/0.1.0/docker-app-linux.tar.gz
--2018-06-18 09:24:32--  https://github.com/docker/app/releases/download/0.1.0/docker-app-linux.tar.gz
Resolving github.com (github.com)... 192.30.253.112, 192.30.253.113
Connecting to github.com (github.com)|192.30.253.112|:443... connected.
HTTP request sent, awaiting response... 404 Not Found
2018-06-18 09:24:32 ERROR 404: Not Found.

Describe the results you expected:
Download the release binary

[vdemeester]

@amarouni thanks for the report, I think #236 will fix that 😉

[vdemeester]

Should be close by #236