Changing AddValues to AddFields and temp disabling adding w time

Currently adding with time is broken, because InfluxDB does not support
using precision for timestamp truncation both with and without
timestamps. This will be re-enabled once we fix InfluxDB to use the
precision argument for truncation in all cases, and a "unit" argument
in the line-protocol for adding points with non-nanosecond stamps

Fixes #175

plugins/kafka_consumer/kafka_consumer.go

@@ -93,7 +93,7 @@ func emitMetrics(k *Kafka, acc plugins.Accumulator, metricConsumer <-chan []byte
 			}
 
 			for _, point := range points {
-				acc.AddValuesWithTime(point.Name(), point.Fields(), point.Tags(), point.Time())
+				acc.AddFieldsWithTime(point.Name(), point.Fields(), point.Tags(), point.Time())
 			}
 		case <-timeout:
 			return nil