testsuite: ScalabilityTestRunner: Change the instance updating states order

Change from update,stop,start  to stop,update,start.
scalability: runScalabilityTestSuite: Initialize retry_time to 2.0
scalability: runScalabilityTestSuite: Fix typo
scalability: runScalabilityTestSuite: Add more logs
scalability: runScalabilityTestSuite: Fix missing self attributes
scalability:runScalabilityTestSuite: Fix path
scalability:runScalabilityTestSuite: Modify _returnFileContentList to join lines
testnode: Use revision for scalability case