Parallize persistent_cache_test and transaction_test

Summary:
Parallize persistent_cache_test and transaction_test
Closes https://github.com/facebook/rocksdb/pull/1506

Differential Revision: D4179392

Pulled By: IslamAbdelRahman

fbshipit-source-id: 05507a1

Makefile

@@ -394,7 +394,9 @@ PARALLEL_TEST = \
 	fault_injection_test \
 	inlineskiplist_test \
 	manual_compaction_test \
-	table_test
+	persistent_cache_test \
+	table_test \
+	transaction_test
 
 SUBSET := $(TESTS)
 ifdef ROCKSDBTESTS_START