use sysinfo() to get ram stats instead of parsing meminfo file.
use sysinfo() to get ram stats instead of parsing meminfo file.

Idea pulled from seculabird gihub user.
see:
https://github.com/secularbird/tmux-mem-cpu-load/commit/880f8b196749ad2ed0ed376db0ba4da0595eeead

allcatsarebeautiful/tmux-mem-cpu-load,thewtex/tmux-mem-cpu-load,allcatsarebeautiful/tmux-mem-cpu-load,allcatsarebeautiful/tmux-mem-cpu-load,thewtex/tmux-mem-cpu-load,thewtex/tmux-mem-cpu-load,allcatsarebeautiful/tmux-mem-cpu-load,thewtex/tmux-mem-cpu-load