Migrate to webpack and npm workflow

**NOTE: Work in progress. Do not merge yet.**

Depends on:

- https://github.com/tidepool-org/tideline/pull/162
- https://github.com/tidepool-org/platform-client/pull/26
- https://github.com/tidepool-org/sundial/pull/7

If you'd like to try this locally, checkout the `nico/workflow` branch locally in each of the dependency repos above, and use npm link, example:

```bash
$ cd tideline/
$ git fetch origin nico/workflow && git checkout -b nico/workflow origin/nico/workflow
$ npm link
# repeat for other dependencies, then:
$ cd ../blip
$ git fetch origin nico/workflow && git checkout -b nico/workflow origin/nico/workflow
$ npm install
$ npm link tideline # <- repeat this for other dependencies
```

**Progress** (list not complete):

- [x] Working webpack/npm workflow for local dev with remote api
- [ ] Working local dev with mock api
- [ ] Build with webpack
- [ ] Make unit tests with webpack
- [ ] Update README
- [ ] Update Shio build and start scripts
- [ ] Clean unused packages and files