Need to make sure parent directory exists before checking morgue out from git

Without this change it fails with the following error message

```
Chef::Exceptions::MissingParentDirectory
----------------------------------------
Cannot clone git[/var/www/morgue] to /var/www/morgue, the enclosing directory /var/www does not exist

Resource Declaration:
---------------------
# In /tmp/vagrant-chef-1/chef-solo-1/cookbooks/morgue/recipes/source.rb

  6:
  7: git "#{node['morgue']['git_checkout_directory']}" do
  8:   repository "#{node['morgue']['git_repo']}"
  9:   reference "#{node['morgue']['git_ref']}"
 10:   action :sync
 11: end
```