Script that runs the pdb locust load tests

The script does:

 - if a commit SHA is given as a parameter, than it checkouts to that and holds the SHA in a variable, needed to name the results folder.
If no SHA is given, it pulls the latest changes from the 6.x branch and copies in a variable the latest commit SHA.

• In the locust results folder, create a folder with <current date without time>-<commit SHA>.
• inside this folder create another two named ingestion-ON and ingestion-OFF
• inside the two folders create folders 1000, 10.000, 100.000 and 500.000

• start pdb
• after pdb started, run locust in the needed results folders (the -csv parameter accepts folder paths) with all queries, with a warmup with one user, another one with -1 user, 10 users and 20 users.
• go to n1 server and start the benchmark with (30 min run interval, 30% data change) and the appropriate number of hosts, depending on the sandbox that's used.
• go to the ingestion results folder and start locust again with the same settings.
• kill the benchmark after locust is done.
• kill pdb.
• inside the results folder delete all files except the .html, _stats.csv and _failures.csv (not sure if we need those). Also the warmup files must be deleted.
• Check the _failures.csv files, and if they are empty, delete them.

!!!!!!! For the 500.000 sandbox you need to change the main sandboxes path.