allow overriding using the LOG_LEVEL env var

Author: hone

lib/rails_stdout_logging/rails.rb

@@ -8,7 +8,7 @@ def self.heroku_stdout_logger
     end
 
     def self.log_level
-      ([::Rails.application.config.log_level.to_s.upcase, "INFO"] & %w[DEBUG INFO WARN ERROR FATAL UNKNOWN]).compact.first
+      ([(ENV['LOG_LEVEL'] || ::Rails.application.config.log_level).to_s.upcase, "INFO"] & %w[DEBUG INFO WARN ERROR FATAL UNKNOWN]).compact.first
     end
 
     def self.set_logger