Update README.md to point to release 1.6 in instructions

README.md

@@ -107,12 +107,12 @@ ACCEPT_KEYWORDS="**" emerge --ask ~games-util/gamemode-9999
 ```
 
 ### Build and Install GameMode
-Then clone, build and install a release version of GameMode at 1.5.1:
+Then clone, build and install a release version of GameMode at 1.6:
 
 ```bash
 git clone https://github.com/FeralInteractive/gamemode.git
 cd gamemode
-git checkout 1.5.1 # omit to build the master branch
+git checkout 1.6 # omit to build the master branch
 ./bootstrap.sh
 ```