Merge pull request #95 from bkon/feature/sudo-docs

Documentation on how to set up password-less sudo for this plugin.

README.md

@@ -92,6 +92,17 @@ config.hostmanager.ip_resolver = proc do |vm, resolving_vm|
 end
 ```
 
+Passwordless sudo
+-----------------
+
+Add  the  following snippet  to  the  sudoers  file (for  example,  to
+```/etc/sudoers.d/vagrant_hostmanager```)  to  make   it  stop  asking
+password when updating hosts  file (replace ```/home/user``` with your
+actual home directory):
+
+    Cmnd_Alias VAGRANT_HOSTMANAGER_UPDATE = /bin/cp /home/user/.vagrant.d/tmp/hosts.local /etc/hosts
+    %sudo ALL=(root) NOPASSWD: VAGRANT_HOSTMANAGER_UPDATE
+
 Windows support
 ---------------