Monitor raspberry pi

Simple script to report RPi temperature/Memory free/CPU used.
Useful for benchmarks, writes to stdout.
Parameters(optional)
--interval (seconds) default 10
--duration (seconds) default 0 (forever)

Example output:
```
21:39:04 "Temp" 40.62 "RAM used" 41.47 "Total CPU" 0.40 "Waiting IO" 0.00 
21:39:14 "Temp" 40.62 "RAM used" 41.47 "Total CPU" 0.20 "Waiting IO" 0.00 
```