[SPARK-11917][PYSPARK] Add SQLContext#dropTempTable to PySpark

Author: Jeff Zhang <zjffdu@apache.org>

Closes #9903 from zjffdu/SPARK-11917.

python/pyspark/sql/context.py

@@ -445,6 +445,15 @@ class SQLContext(object):
         else:
             raise ValueError("Can only register DataFrame as table")
 
+    @since(1.6)
+    def dropTempTable(self, tableName):
+        """ Remove the temp table from catalog.
+
+        >>> sqlContext.registerDataFrameAsTable(df, "table1")
+        >>> sqlContext.dropTempTable("table1")
+        """
+        self._ssql_ctx.dropTempTable(tableName)
+
     def parquetFile(self, *paths):
         """Loads a Parquet file, returning the result as a :class:`DataFrame`.