asadiqbal08/SOL-766: Add Facebook sharing to certificate view

* updated the flags for social media sharing
* added facebook feed ui to share public url
* update the condition logic
* update the code as per suggestion and added pick new style for share buttons
* update the css class reference
* update the bok-choy test
* updated description and some text touch-ups
* moved the JS related to facebook into separate location
* js formatting
* Add trailing comma per chrisndodge
* Add wait to fix flaky test...maybe

lms/static/js/utils/facebook.js

@@ -0,0 +1,32 @@
+var FaceBook = (function() {
+    var _args = {};
+
+    return {
+        init : function (Args) {
+            _args = Args;
+            window.fbAsyncInit = function() {
+                FB.init({
+                    appId      : _args.facebook_app_id,
+                    xfbml      : true,
+                    version    : 'v2.3'
+                });
+            };
+            (function(d, s, id){
+                var js, fjs = d.getElementsByTagName(s)[0];
+                if (d.getElementById(id)) {return;}
+                js = d.createElement(s); js.id = id;
+                js.src = "//connect.facebook.net/en_US/sdk.js";
+                fjs.parentNode.insertBefore(js, fjs);
+            }(document, 'script', 'facebook-jssdk'));
+        },
+        share: function (feed_data) {
+            FB.ui({
+                method: 'feed',
+                name: feed_data['share_text'],
+                link: feed_data['share_link'],
+                picture: feed_data['picture_link'],
+                description: feed_data['description']
+            });
+        }
+    };
+}());