use oxide

- Setup the codebase to be able to use the Rust parts based on an
  environment variable: `OXIDE=1`.
- Setup some tests that run both the non-Rust and Rust version in the
  same test.
- Sort the candidates in a consistent way, to guarantee the order for
  now (especially in tests).
- Reflect sorting related changes in tests.
- Ensure tests run in both the Rust and non-Rust version. (Some tests
  are explicitly skipped when using the Rust version since we haven't
  implemented those features yet. These include: custom prefix,
  transformers and extractors).
  - `jest`
  -`OXIDE=1 jest`

src/util/negateValue.js

@@ -1,4 +1,4 @@
-export default function (value) {
+export default function negateValue(value) {
   value = `${value}`
 
   if (value === '0') {