Fix typo in README

This commit 51a9fbf changed the default channel from 'test' to 'stable'

Signed-off-by: Daniel Fernández <daferoes@gmail.com>

Author: danifr

README.md

@@ -24,7 +24,7 @@ curl -fsSL https://test.docker.com -o test-docker.sh
 sh test-docker.sh
 ```
 
-From the source repo (This will install latest from the `test` channel):
+From the source repo (This will install latest from the `stable` channel):
 ```shell
 sh install.sh
 ```