While the PHPCPD and PHPUnit tools use the [same function under the hood](1fa3ba1b16/src/tools.ts (L461-L473)), I have the impression that the `function` keyword should be the tool name.
If that's correct, this should fix it.
Added fetch_latest to tools.json. When fetch_latest is true for a tool
it will fetch the release.atom for the tool and parse that to get the
latest release.
Bumped lib version to ES2020 in tsconfig.json for string.matchAll.