updated description for mutli-exec (redis#219)

Author: slice4e

redis_benchmarks_specification/test-suites/memtier_benchmark-1Mkeys-hash-transactions-multi-exec-pipeline-20.yml

@@ -1,6 +1,6 @@
 version: 0.4
 name: memtier_benchmark-1Mkeys-hash-transactions-multi-exec-pipeline-20
-description: Runs memtier_benchmark, for a keyspace length of 1M keys with a data size of 100 Bytes for each key, focusing on the MULTI EXEC scenario. TODO - this descriotion needs fixing. We either need a preload command to populate 1M keys, or we need to modify this description. 
+description: Runs memtier_benchmark for MULTI EXEC scenario - executing commands as a transaction. The transaction sets fields in a hash, checks if they exist, retrieves them and finally deletes them. At the end of execution there are no keys in the database. 
 tested-groups:
 - transactions
 - hash