checkout v1.2 to match current branch

install.sh

@@ -9,7 +9,7 @@ if ! [ -d ./assets/oauth3.org ]; then
   git clone https://git.daplie.com/OAuth3/oauth3.js.git ./assets/oauth3.org
 fi
 pushd ./assets/oauth3.org
-  git checkout v1
+  git checkout v1.2
   git pull
 popd