bugalertUpdate.py issues - Invalid command & missing node check

[tu-arista]

Hey Mark!
I tried out your bugalertUpdate script, it has two issues but which are easy to fix:

• In the second command in each of the following lines, cvp needs to be changed to cvpi

Arista_scripts/bugalertUpdate.py

Line 189 in 84b3cd2

stdin, stdout, stderr = ssh.exec_command('cvpi stop bugalerts-update && cvp start bugalerts-update')

Arista_scripts/bugalertUpdate.py

Line 219 in 84b3cd2

stdin, stdout, stderr = ssh.exec_command('cvpi stop bugalerts-update && cvp start bugalerts-update')

• The check for the number of nodes is missing after line 180, I assume that the environment variables (e.g., $SECONDARY_HOSTNAME) are only populated when there is more than one node running - The lab I tested
  this in was running only one. This should be fixed by adding the same check which you did in the lines here:

Arista_scripts/bugalertUpdate.py

Lines 209 to 210 in 84b3cd2

	stdin, stdout, stderr = ssh.exec_command('kubectl get nodes | grep Ready | wc -l')
	if stdout == "3":

Apart from that, the CLI instructions worked for me and I could update the AlertBase-CVP.json in my lab,
thanks for this script! :)