Fixes to RateTestHandler

Several fixes to RateTestHandler.py

• now upload monitoring.json and RateTest*.log to eos
• update url and upload path
• fix code to obtain ref rate, need some test on it
• upload log files of rate test to eos even the handler failed to parse it, would be helpful for debugging

The test data are also changed, but not finalised, will update them soon.

cc @abertoli @nskidmor

link to DPA WP1 task lhcb-dpa/project#90