Cleanup user directories if state was leftover from previous run

We are seeing failures in our CI relating to state not being cleaned
up in a previous run:

```
  1) Chef::Provider::User::Useradd action :create when the user already exists and home directory is updated and manage_home is enabled moves the home directory to the new location
     Failure/Error: user_resource.run_action(:create)
     Mixlib::ShellOut::ShellCommandFailed:
       user[TEST USER RESOURCE] (dynamically defined) had an error: Mixlib::ShellOut::ShellCommandFailed: Expected process to exit with [0], but received '12'
       ---- Begin output of ["usermod", "-d", "/home/bar", "-m", "cf-test"] ----
       STDOUT:
       STDERR: usermod: directory /home/bar exists
       ---- End output of ["usermod", "-d", "/home/bar", "-m", "cf-test"] ----
       Ran ["usermod", "-d", "/home/bar", "-m", "cf-test"] returned 12
     # ./lib/chef/mixin/shell_out.rb:56:in `shell_out!'
     # ./lib/chef/provider/user/useradd.rb:42:in `manage_user'
     # ./lib/chef/provider/user.rb:137:in `block in action_create'
     # ./lib/chef/mixin/why_run.rb:52:in `call'
     # ./lib/chef/mixin/why_run.rb:52:in `add_action'
     # ./lib/chef/provider.rb:180:in `converge_by'
     # ./lib/chef/provider/user.rb:136:in `action_create'
     # ./lib/chef/provider.rb:145:in `run_action'
     # ./lib/chef/resource.rb:561:in `run_action'
     # ./spec/functional/resource/user/useradd_spec.rb:336:in `block (4 levels) in <top (required)>'
```

1 files changed, 10 insertions, 0 deletions

diff --git a/spec/functional/resource/user/useradd_spec.rb b/spec/functional/resource/user/useradd_spec.rb
index 852f2eb083..ceae81aab9 100644
--- a/spec/functional/resource/user/useradd_spec.rb
+++ b/spec/functional/resource/user/useradd_spec.rb
@@ -77,9 +77,19 @@ describe Chef::Provider::User::Useradd, metadata do
     end
   end
 
+  def try_cleanup
+    ['/home/foo', '/home/bar'].each do |f|
+      shell_out("rm", "-r", f)
+    end
+    ['cf-test'].each do |u|
+      shell_out("userdel", "-r", username)
+    end
+  end
+
   before do
     # Silence shell_out live stream
     Chef::Log.level = :warn
+    try_cleanup
   end
 
   after do