Merge pull request #1539 from fkautz/https-install-script

Install script should be fetched over https, not http.

README.md

@@ -147,7 +147,7 @@ Quick install on Ubuntu 12.04 and 12.10
 ---------------------------------------
 
 ```bash
-curl get.docker.io | sudo sh -x
+curl https://get.docker.io | sudo sh -x
 ```
 
 Binary installs