[Piuparts-reports] Cron <piupartsm at pejacevic> rotate_master_logs

[Cron Daemon]

'stretch2buster/master.log' -> 'stretch2buster/master.20180730.log'
'stretch2proposed/master.log' -> 'stretch2proposed/master.20180730.log'
jessie2bpo2stretch/master.20180729.log: 61.4 KiB / 1037.1 KiB = 0.059
wheezy-security/master.20180729.log: 63.6 KiB / 1027.4 KiB = 0.062