Dart API wrapper for the Skycoin node API

## Expected Behavior

Access to the Skycoin node REST API implemented in Dart code or as an assembly.

## Actual Behavior

Right now this is not possible.

## Specifications

- Version: 0.25.1
- Platform: all
- Subsystem: all exported API sets

## Possible Solution

Generate with Swagger (share more info, please) . Beware of CSRF .

- [ ] Use Skycoin node Swagger spec to generate initial Dart REST API client
- [ ] Add `make` target to automate generation in `./build`
- [ ] Aforementioned target should copy / merge relevant files into source code tree
- [ ] README explaining the process
- [ ] Mention in CHANGELOG
- [ ] Patch the result Swagger-gen REST client to support specifying node address
- [ ] Update package metadata
- [ ] Run basic Swagger tests in Travis
- [ ] Unify testing code if multiple frameworks are used across source tree
- [ ] Beware of CSRF auth