At, the least "/" should behave the same as "".

Currently the module field on package.json points to src/simpla.js but really it should point to a separate build, that's been transpiled, but not bundled. This means that whatever module bundling system consumers are using will still be used, but it won't need to be transpiled. As it currently stands, users can come up against [this bug](https://github.com/facebookincubator/create-react-app

We should have a test that validates each service can actually be resolved from the container (within a scope). See #339 for motivation. It would be fantastic if this could be done via reflection and not manually adding a new test every time you register a new service. I'm thinking we would define a static member that contained all the ServiceDescriptors. Then in the test we just get this member