fix sql and streaming doc warnings

Author: mengxr

python/pyspark/sql/dataframe.py

@@ -943,6 +943,7 @@ def replace(self, to_replace, value, subset=None):
             Columns specified in subset that do not have matching data type are ignored.
             For example, if `value` is a string, and subset contains a non-string column,
             then the non-string column is simply ignored.
+
         >>> df4.replace(10, 20).show()
         +----+------+-----+
         | age|height| name|

python/pyspark/streaming/kafka.py

@@ -132,11 +132,12 @@ def createRDD(sc, kafkaParams, offsetRanges, leaders={},
         .. note:: Experimental
 
         Create a RDD from Kafka using offset ranges for each topic and partition.
+
         :param sc:  SparkContext object
         :param kafkaParams: Additional params for Kafka
         :param offsetRanges:  list of offsetRange to specify topic:partition:[start, end) to consume
         :param leaders: Kafka brokers for each TopicAndPartition in offsetRanges.  May be an empty
-                        map, in which case leaders will be looked up on the driver.
+            map, in which case leaders will be looked up on the driver.
         :param keyDecoder:  A function used to decode key (default is utf8_decoder)
         :param valueDecoder:  A function used to decode value (default is utf8_decoder)
         :return: A RDD object