Fix unused variable warnings

lib/split/alternative.rb

@@ -15,7 +15,7 @@ def initialize(name, experiment_name)
         @name = name
         @weight = 1
       end
-      p_winner = 0.0
+      @p_winner = 0.0
     end
 
     def to_s
@@ -122,7 +122,7 @@ def z_score(goal = nil)
       # can't calculate zscore for P(x) > 1
       return 'N/A' if p_a > 1 || p_c > 1
 
-      z_score = Split::Zscore.calculate(p_a, n_a, p_c, n_c)
+      Split::Zscore.calculate(p_a, n_a, p_c, n_c)
     end
 
     def extra_info

lib/split/combined_experiments_helper.rb

@@ -31,7 +31,7 @@ def find_combined_experiment(metric_descriptor)
       raise(Split::InvalidExperimentsFormatError, 'Invalid descriptor class (String or Symbol required)') unless metric_descriptor.class == String || metric_descriptor.class == Symbol
       raise(Split::InvalidExperimentsFormatError, 'Enable configuration') unless Split.configuration.enabled
       raise(Split::InvalidExperimentsFormatError, 'Enable `allow_multiple_experiments`') unless Split.configuration.allow_multiple_experiments
-      experiment = Split::configuration.experiments[metric_descriptor.to_sym]
+      Split::configuration.experiments[metric_descriptor.to_sym]
     end
   end
 end

lib/split/helper.rb

@@ -80,7 +80,7 @@ def ab_finished(metric_descriptor, options = {:reset => true})
 
     def ab_record_extra_info(metric_descriptor, key, value = 1)
       return if exclude_visitor? || Split.configuration.disabled?
-      metric_descriptor, goals = normalize_metric(metric_descriptor)
+      metric_descriptor, _ = normalize_metric(metric_descriptor)
       experiments = Metric.possible_experiments(metric_descriptor)
 
       if experiments.any?