Invalid disk space recognition

[blackandred]

"disk-space": {
            "ident": "disk-space=True",
            "output": "There is 5.7GB disk space at '/', nothing to worry about, defined minimum is 6GB\n",
            "status": true
        }

[blackandred]

Still an issue - there is a suggestion to maybe rewritte it to Python due to differences between bash/sh versions in runtime environment.

[blackandred]

Resolved with #3