Changelog:
- f408c30 Adding token validation to CircleAPI class [[3](https://github.com/TheRealJoeLinux/circlecli/issues/3)]
- 3bb3f78 Adding ability to use CIRCLE_TOKEN environment variable as token override [[4](https://github.com/TheRealJoeLinux/circlecli/issues/4)]
- 8263fef Adding subkey filtering (using dots)
- ee8d463 Adding basic filtering