New Rule: UUIDv4

[CSenshi]

Rule Name: UUIDv4

Rule Description: The field under validation must be a valid Universally Unique IDentifier version 4 (UUIDv4). UUIDv4 is random based.

Rule Usage Example:

reqs = {'data' : '81368b76-31e9-41db-b28c-8c029cb435f0'}
rule = {'data' : 'uuidv4'}
validate(reqs, rule) # True

reqs = {'data' : 'a3bb189e-8bf9-3888-9912-ace4e6543002'}
rule = {'data' : 'uuidv4''}
validate(reqs, rule) # False, It fails because data is uuidv3

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Before contributing please review RULES.md (check for duplication), also check CONTRIBUTING.md for more details :100:

[dbejanishvili]

I can work on that