Added questions for System administration / IT operations, Monitoring, network administration

After discussing this in a recent issue (URL: https://github.com/ChiperSoft/InterviewThis/issues/14) I added some questions for system/network administration and monitoring/on-call duty stuff.

Based on my 10+ years experience of working in IT, with a focus on Linux setups in bigger environments.
But most questions are very basic and show that system administration is not a part that can live on its own. Exchange with developers and operating is vital to succeed.