chore(deps): update dependency rss to v0.3.0

Gemfile.lock

@@ -81,10 +81,10 @@ GEM
     rb-inotify (0.10.1)
       ffi (~> 1.0)
     redcarpet (3.6.0)
-    rexml (3.2.5)
+    rexml (3.2.6)
     rouge (1.11.1)
     rr (3.1.0)
-    rss (0.2.9)
+    rss (0.3.0)
       rexml
     ruby2_keywords (0.0.5)
     sass (3.7.4)