Prior to the Hashie::Mash integration in 1.0.0, Confstruct's internal keys were canonicalized to symbols, as evidence if you called #keys on one of em. Hashie::Mash uses Strings instead, so with the Hashie::Mash merge they used Strings instead. At first I thought, eh, this isn't a big deal, who goes looking at the #keys of their configuration objects much? But I realized, after trying to incorporate it into my already existing app, that it ends up effecting a lot more -- such as `ordinary_hash.merge(confstruct_hash)`. Ends up creating all sorts of hard to deal with byproduct changes. Fortunately, Hashie::Mash is written well and allows us to switch (back) to Symbols by overriding one simple DRY convert_keys method. So we do so, restoring backwards compat with previous versions of Confstruct. Suggest release as 1.0.1.