notifier config improvements: db dir, email vars

- specify notifier_db_dir as a setting.  Had previously just stuck
  under $HOME, but Jim preferred as a distinct setting.

- pass through email settings env variables

- plumb through django's EMAIL_USE_TLS setting.  Required to be
  able to send mail using Amazon SES.  They speak smtp, but only
  over TLS.

playbooks/roles/notifier/defaults/main.yml

@@ -4,6 +4,7 @@ notifier_user: "notifier"
 notifier_web_user: "www-user"
 notifier_home: "/opt/wwc/notifier"
 notifier_venv_dir: "{{ notifier_home }}/virtualenvs/notifier"
+notifier_db_dir: "{{ notifier_home }}/db"
 notifier_source_repo: "git@github.com:edx/notifier.git"
 notifier_code_dir: "{{ notifier_home }}/src"
 notifier_version: "master"
@@ -20,7 +21,7 @@ notifier_email_host: "localhost"
 notifier_email_port: 25
 notifier_email_user: ""
 notifier_email_pass: ""
-notifier_email_host: ""
+notifier_email_use_tls: "False"
 
 notifier_email_domain: "notifications.edx.org"
 notifier_email_rewrite_recipient: ""
@@ -62,7 +63,13 @@ notifier_debian_pkgs:
 #
 notifier_env_vars:
   NOTIFIER_ENV: "{{ notifier_env }}"
+  NOTIFIER_DB_DIR: "{{ notifier_db_dir }}"
   EMAIL_BACKEND: "{{ notifier_email_backend }}"
+  EMAIL_HOST: "{{ notifier_email_host }}"
+  EMAIL_PORT: "{{ notifier_email_port }}"
+  EMAIL_HOST_USER: "{{ notifier_email_user }}"
+  EMAIL_HOST_PASSWORD: "{{ notifier_email_pass }}"
+  EMAIL_USE_TLS: "{{ notifier_email_use_tls }}"
   EMAIL_DOMAIN: "{{ notifier_email_domain }}"
   EMAIL_REWRITE_RECIPIENT: "{{ notifier_email_rewrite_recipient }}"
   LMS_URL_BASE: "{{ notifier_lms_url_base }}"

playbooks/roles/notifier/tasks/main.yml

@@ -125,9 +125,9 @@
   - install
   - update
 
-- name: notifier | create notifier/db directory
+- name: notifier | create notifier DB directory
   file:
-    path="{{ notifier_home }}/db" mode=2775 state=directory
+    path="{{ notifier_db_dir }}" mode=2775 state=directory
   tags:
   - notifier
   - install