Enable DBTest.GroupCommit as it runs in a reasonlable time now.

Summary:
Remove ReRuns as they only waste time.
  Add env_basic_test to get more foundation coverage.
Closes https://github.com/facebook/rocksdb/pull/1788

Differential Revision: D4431433

Pulled By: IslamAbdelRahman

fbshipit-source-id: 50d07f8

appveyor.yml

@@ -11,7 +11,7 @@ build:
   verbosity: minimal
 test:
 test_script:
-- ps: build_tools\run_ci_db_test.ps1 -EnableRerun -Run db_test2 -Concurrency 8
-- ps: build_tools\run_ci_db_test.ps1 -EnableRerun -Run db_test -Exclude DBTest.GroupCommitTest -Concurrency 10
-- ps: build_tools\run_ci_db_test.ps1 -Run env_test -Concurrency 1
+- ps: build_tools\run_ci_db_test.ps1 -Run db_test2 -Concurrency 8
+- ps: build_tools\run_ci_db_test.ps1 -Run db_test -Concurrency 8
+- ps: build_tools\run_ci_db_test.ps1 -Run env_test,env_basic_test -Concurrency 2