Simplify load_alternatives from config

Author: andrehjr

lib/split/experiment_storage.rb

@@ -57,11 +57,9 @@ def exists?
       def load_alternatives
         alts = Split.configuration.experiment_for(@name)[:alternatives]
         raise ArgumentError, "Experiment configuration is missing :alternatives array" unless alts
-        if alts.is_a?(Hash)
-          alts.keys
-        else
-          alts.flatten
-        end
+
+        alts = alts.keys if alts.is_a?(Hash)
+        alts.flatten
       end
 
       def load_metadata