let app home directories default to None if not defined

playbooks/roles/local_dev/defaults/main.yml

@@ -43,28 +43,28 @@ localdev_accounts:
 
     - {
         user: "{{ analytics_api_user|default('None') }}",
-        home: "{{ analytics_api_home }}",
+        home: "{{ analytics_api_home|default('None') }}",
         env: "analytics_api_env",
         repo: "analytics_api"
       }
 
     - {
         user: "{{ insights_user|default('None') }}",
-        home: "{{ insights_home }}",
+        home: "{{ insights_home|default('None') }}",
         env: "insights_env",
         repo: "edx_analytics_dashboard"
       }
 
     - {
         user: "{{ programs_user|default('None') }}",
-        home: "{{ programs_home }}",
+        home: "{{ programs_home|default('None') }}",
         env: "programs_env",
         repo: "programs"
       }
 
     - {
         user: "{{ credentials_user|default('None') }}",
-        home: "{{ credentials_home }}",
+        home: "{{ credentials_home|default('None') }}",
         env: "credentials_env",
         repo: "credentials"
       }