Set min version of daedalus-core to 0.0.3.

This is to make sure that users get the version that doesn't trigger lots of
deprecation warnings under MRI 2.1.0.
Handle infinite Dir.glob wildcards.

This commit fixes `Dir.glob()` so that it accepts patterns such as
`**/**/**/**/**` and so forth. Previously this would trigger a coercion error.

This fixes #2478.