libuuid mixes up str and string

[sinistersnare]

The libuuid documentation (and henceforth the source code itself) mixes up string and str in method signatures, specifically the name of the method itself.

Proposed changes:

• fn to_simple_str(&self) -> String => fn to_simple_string(&self) -> String
• fn to_hyphenated_str(&self) -> String => fn to_hyphenated_string(&self) -> String
• fn to_urn_str(&self) -> String => fn to_urn_string(&self) -> String
• fn parse_string(us: &str) -> Result<Uuid, ParseError> => fn parse_str(us: &str) -> Result<Uuid, ParseError>

[sinistersnare]

Going to close this and open an issue / send a PR to here