[New Analyzer] Rust

[ZapAnton]

I'd like to create an analyzer for Rust.

I have developed a basic prototype, that conforms to the Interface and does a primitive analysis of the reverse-string exercise (basically compares the solution with the prepared AST).
The reverse-string exercise was chosen instead of two-fer, because two-fer was deemed unsuitable for the track and later deprecated. Currently reverse-string is the first core exercise.

[iHiD]

@ZapAnton Great! :)

I have:

• Created https://github.com/exercism/rust-analyzer
• Invited you to a team for it
• Sent you data on Slack