Add two additional PATH env checks for the rule 'os-04'

[MikhailAseev]

Description

I suggest adding two checks for the rule 'os-04' for PATH environment variable:

• check that there are no spaces;
• check that there are no '..' (parent directory of the current one).

I guess it won't be superfluous.

Solution

Can be easily solved as:

...
    its('split') { should_not include(' ') }
    its('split') { should_not include('..') }
...