boa-cat 0.7.0

Tree-walking ECMAScript interpreter built on ecma-syntax-cat. v0.7.0 bumps to ecma-parse-cat 0.3 so the async track's tests can drop their `(async function () { ... })()` IIFE workarounds and use natural `async () => body` arrow syntax + `obj.catch(cb)` dot-member access. No engine source change: the AST variants for these forms have been handled since v0.6; this release picks up the parser support.