OSInfo singleton

[AlonZivony]

The OSInfo struct gets the system information upon initialization.
This information currently is a static information - OS version, distro, etc.
So, unless I am missing something, I propose to implement the type init function as a singleton getter, which initialize it only once per program runtime.
This way you can access it from many places in the code without fearing the performance consequences of it.

[geyslan]

sync.Once could be the way.

[AlonZivony]

Yea the implementation seems to me trivial.
Opened the issue to discuss if to implement this.

[rafaeldtinoco]

Actually: #297