Fix logging at level Logger::DEBUG

Previously setting the log level to Logger::DEBUG would have no effect
as the log level of the Logger object was not changed.

If you set:

    InfluxDB::Logging.log_level = Logger::DEBUG

InfluxDB::Logging::log? would return true, allowing the log statement to
proceed, but #log would not do anything because the Logger object was
still at its default from initialization, Logger::INFO.

By setting the log level directly on the Logger object and removing
::log? we allow the Logger object to determine if a log level needs to
be logged or not.

This allows debug-level log messages to be displayed.

Author: drbrain

lib/influxdb/logging.rb

@@ -6,7 +6,6 @@ module Logging # :nodoc:
 
     class << self
       attr_writer :logger
-      attr_writer :log_level
 
       def logger
         return false if @logger == false
@@ -15,26 +14,20 @@ def logger
       end
 
       def log_level
-        @log_level || Logger::INFO
+        logger&.level || Logger::INFO
       end
 
-      def log?(level)
-        case level
-        when :debug then log_level <= Logger::DEBUG
-        when :info  then log_level <= Logger::INFO
-        when :warn  then log_level <= Logger::WARN
-        when :error then log_level <= Logger::ERROR
-        when :fatal then log_level <= Logger::FATAL
-        else true
-        end
+      def log_level=(level)
+        return unless logger
+
+        logger.level = level
       end
     end
 
     private
 
     def log(level, message = nil, &block)
       return unless InfluxDB::Logging.logger
-      return unless InfluxDB::Logging.log?(level)
 
       if block_given?
         InfluxDB::Logging.logger.send(level.to_sym, PREFIX, &block)