Support Redis password

[earthlyreason]

Thanks for creating and maintaining this extension.

We are using ckanext-harvest in a Heroku environment, where the Redis add-on has a URL that includes a u/p, like redis://x:yz@host:port.

It appears that Harvest cannot be used when Redis requires a password.

Would the following patch be an appropriate way to use the ckan.harvest.mq.password setting that is used for the amqp connection?

--- a/ckanext/harvest/queue.py
+++ b/ckanext/harvest/queue.py
@@ -64,6 +64,7 @@ def get_connection_redis():
     import redis
     return redis.StrictRedis(host=config.get('ckan.harvest.mq.hostname', HOSTNAME),
                           port=int(config.get('ckan.harvest.mq.port', REDIS_PORT)),
+                          password=config.get('ckan.harvest.mq.password', None),
                           db=int(config.get('ckan.harvest.mq.redis_db', REDIS_DB)))

Perhaps related is ckan/ckan#3165, which adds a CKAN_REDIS_URL option to core CKAN (as noted in #257). When present, that setting might provide a better default now for the Redis connection.

[amercader]

Fixed in #332