use explicit versions

README.md

@@ -402,8 +402,8 @@ Greenlock comes with reasonable defaults but when you install it,
 you should also install any plugins that you need.
 
 ```bash
-npm install --save @root/greenlock
-npm install --save greenlock-manager-fs
+npm install --save @root/greenlock@v4
+npm install --save @greenlock/manager
 npm install --save greenlock-store-fs
 npm install --save acme-http-01-standalone
 ```