Fixes #119: More robust instructions for role installation.

README.md

@@ -63,7 +63,7 @@ Note for Linux users: *If NFS is not already installed on your host, you will ne
     - Copy `example.config.yml` to `config.yml`.
   3. Create a local directory where Drupal will be installed and configure the path to that directory in `config.yml` (`local_path`, inside `vagrant_synced_folders`).
   4. Open Terminal, cd to this directory (containing the `Vagrantfile` and this README file).
-  5. [Mac/Linux only] Install Ansible Galaxy roles required for this VM: `$ sudo ansible-galaxy install -r provisioning/requirements.txt`
+  5. [Mac/Linux only] Install Ansible Galaxy roles required for this VM: `$ sudo ansible-galaxy install -r provisioning/requirements.txt --force`
   6. Type in `vagrant up`, and let Vagrant do its magic.
 
 Note: *If there are any errors during the course of running `vagrant up`, and it drops you back to your command prompt, just run `vagrant provision` to continue building the VM from where you left off. If there are still errors after doing this a few times, post an issue to this project's issue queue on GitHub with the error.*