A few npm dependencies were major versions behind, so this updates `yargs`,
`fs-extra`, and `jasmin-spec-reporter` to their latest versions.
The major change here is `fs-extra`, which now has promise implementations
of all functions by default, this means there's no reason to manually
`Promisify` a function any more, the result is less code overall.
There is one important edge case, `fs-extra` uses built-in native Node
promises, which do not have a `finally` function. If you start a promise
change with an `fs-extra` function, you need to wrap it in `Promise.resolve`
in order to make use of finally at the end (assuming you are using finally
at all, if not you don't need to worry about it. The upside is that your
code will always error if you forget to do this.
