Add tests for SQLite based logging

.travis.yml

@@ -29,3 +29,4 @@ addons:
     - python-configparser
     - python-pyasn1
     - python-openssl
+    - python-sqlite2

certidude/templates/server/server.conf

@@ -53,9 +53,11 @@ request subnets = 0.0.0.0/0
 autosign subnets = 127.0.0.0/8 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16
 
 [logging]
-backend =
+# Disable logging
+;backend =
 
-;backend = sql
+# Use SQLite backend
+backend = sql
 database = sqlite://{{ directory }}/db.sqlite
 
 [signature]