Change Discourse feed widget params

rssmikle_url:
"http://discuss.okfn.org/category/open-knowledge-labs.rss" (specific
labs rss feed instead of general OKFN rss feed)
rssmikle_title_bgcolor: "#7ab800" (to match site theme colors)
rssmikle_item_title_color: "#22998B"
responsive: "on" (to fill its container and make it work on mobile, too)
scrollstep: “6”
Merge pull request #262 from danfowler/tweaks-to-discourse-feed-widget

Change Discourse feed widget params