…ll be used to determine how

long job is run in raw seconds. This will be used when --timeout is specified to cancel job if elapsed time
has exceeded timeout value

cancel if elapsed time exceeds test timeout

…completed jobs

also update the calcuation for total runtime when its a batch job to use elapsed time

…e this for cancelling job

when pendtime exceeds maxpendtime

… in Job class.

We use this variable as reference point when job was submitted to calculate pending time using time.time().
This will avoid us from having to query the scheduler for the elapsed pending time. We use this to determine when to cancel
job

…ndtime exceeds maxpendtime.

These methods are defined in BaseExecutor class which can be invoked in each executor method.
Add this implementation for slurm and lsf scheduler to call these methods.
round calculation to 2 decimals for calculating elapsedtime and pendtime.
also print pendtime and elapsedtime as columns into the table

also fix an issue when using 1 sec poll interval with slurm where sacct
can't retrieve the job state. For this we sleep 0.1 sec if job state is
not retrieved and retry again.