Keep use of interfaces in readme simple and CVSS version agnostic.

[jsvob]

Closes #71

It might seem as a WONTFIX issue, but to be frank, I was confused for 10 minutes about that too.

[jobselko]

I think we should make all the examples consistent to avoid any misunderstanding about why CVSS4 includes something that CVSS3 or CVSS2 do not, and so on:

    vector = 'AV:L/AC:L/Au:M/C:N/I:P/A:C/E:U/RL:W/RC:ND/CDP:L/TD:H/CR:ND/IR:ND/AR:M'
    c = CVSS2(vector)
    print(vector)
    print(c.clean_vector())
    print(c.scores())
    print(c.severities())

    print()

    vector = 'CVSS:3.0/S:C/C:H/I:H/A:N/AV:P/AC:H/PR:H/UI:R/E:H/RL:O/RC:R/CR:H/IR:X/AR:X/MAC:H/MPR:X/MUI:X/MC:L/MA:X'
    c = CVSS3(vector)
    print(vector)
    print(c.clean_vector())
    print(c.scores())
    print(c.severities())

    print()

    vector = 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:N'
    c = CVSS4(vector)
    print(vector)
    print(c.clean_vector())
    print(c.scores())
    print(c.severities())

    print()

[skontar]

I agree with both of you. I would actually like it this way:

...
    c = CVSS4(vector)
    print(vector)
    print(c.clean_vector())
    print(c.scores())
    print(c.severities())
    # Since CVSS4 has only one score and severity, attributes can be used instead if prefered
    print(c.base_score)
    print(c.severity)  
...

[jobselko]

@skontar cvss2.base_score and cvss3.base_score work as well (but cvss2.severity and cvss3.severity do not), so it might be better just to omit it, but no strong preference

[jsvob]

Thank you all for review. Went with Jitka's suggestion. Subjective reasons:

• Simple.
• Interface usage kept consistent.
• Nonconfusing for people not familiar with the code.
• The version-specific property interfaces can be discovered by reading the implementation. For those who don't do that, information about that can be superfluous, unasked for, confusing. And those who do it discover it.

Is that fine @skontar ? (I know, bikeshedding at this point 😺 )

[skontar]

That is also fine with me. Maybe just add a comment that it is expected in v4 to return tuple of just one value due to v4 spec?

[jobselko]

The PR title could also be updated to better reflect the changes, but otherwise, LGTM.