Fix to follow redirect

As per git-tips#154, change to -L so that the redirect gets followed. As written this line downloads the html redirect page.

Author: mvolz

README.md

@@ -372,7 +372,7 @@ git add -p
 
 ## Get git bash completion
 ```sh
-curl http://git.io/vfhol > ~/.git-completion.bash && echo '[ -f ~/.git-completion.bash ] && . ~/.git-completion.bash' >> ~/.bashrc
+curl -L http://git.io/vfhol > ~/.git-completion.bash && echo '[ -f ~/.git-completion.bash ] && . ~/.git-completion.bash' >> ~/.bashrc
 ```
 
 ## What changed since two weeks?