Bug fixes

• URLDecoder: Illegal hex characters in escape (%) pattern - For input string: " S" [ISSUE] #747
• ERROR NetworkClient: Node [127.0.0.1:9200] failed (Read timed out); no other nodes left - aborting... [ISSUE] #753
• Elasticsearch Mapreduce write "es.mapping.exclude" not working [ISSUE] #752
• PROBLEM: Failed to write data back to ES by using Spark DataFrame save() API !! [ISSUE] #749
• NetworkClient: Invalid target URI POST@null/pharmadata/test/_search [ISSUE] #748
• Pushdown option not working as expected with Spark data frames [ISSUE] #734
• Unhandled Exception in org.elasticsearch.spark.rdd.EsRDDWriter.write, and rdd wouldn't stop. [ISSUE] #719