Move installer roles into roles directory

Signed-off-by: Shane McDonald <me@shanemcd.com>

installer/roles/check_vars/tasks/check_docker.yml

@@ -0,0 +1,14 @@
+# check_docker.yml
+---
+- name: postgres_data_dir should be defined
+  assert:
+    that:
+    - postgres_data_dir is defined and postgres_data_dir != ''
+    msg: "Set the value of 'postgres_data_dir' in the inventory file."
+  when: pg_hostname is not defined or pg_hostname == ''
+
+- name: host_port should be defined
+  assert:
+    that:
+    - host_port is defined and host_port != ''
+    msg: "Set the value of 'host_port' in the inventory file."