Clarify the .ansible.cfg settings and fix mislabled tag

Change-Id: I5cd90b25d14a3ceab7682dcec05adb0949c6330f

README.md

@@ -102,8 +102,9 @@ sudo vagrant plugin install vagrant-cachier
 To edit the Ansible roles I suggest downloading the full git source of the role and putting it in
 your ansible path. Then though you can rerun `vagrant provision` to test your changes, often it is
 easier to run ansible directly. For this to work smoothly add these vagrant specific settings to
-your local ansible configuration
+your local ansible configuration (~/.ansible.cfg):
 
+    [defaults]
     hostfile = .vagrant/provisioners/ansible/inventory/vagrant_ansible_inventory
     private_key_file = ~/.vagrant.d/insecure_private_key
     remote_user = vagrant

mini-mon.yml

@@ -81,7 +81,7 @@
        kafka_uri: "{{kafka_hosts}}",
        influxdb_user: mon_persister,
        influxdb_password: password,
-       tags: [influxdb]}
+       tags: [persister]}
     - {role: tkuhlman.monasca-notification,
        mysql_user: notification,
        mysql_password: password,