Bump parity 3.0.1 -> 3.1.0
Bump parity 3.0.1 -> 3.1.0

https://github.com/thoughtbot/parity/releases/tag/3.1.0

```
shasum -a 256 parity-3.1.0.tar.gz
c804bca89d99f8cfacde6098959a198b9ef347ad8ce40759133fd766206d7b04  parity-3.1.0.tar.gz
```

thoughtbot/homebrew-formulae