Build and deploy kernel with CircleCI to packagecloud

[StefanScherer]

Did we any deployment to package cloud with CircleCI yet?

As the circle.yml only deploys on tagged builds with vx.x.x I think we uploaded the kernel manually to packagecloud in the past.

deployment:
  release:
    tag: /v[0-9]+(\.[0-9]+)*/
    commands:
      - package_cloud push hypriot-uploader/rpi/debian/jessie $CIRCLE_ARTIFACTS/*.deb

The circle.yml has a deployment section, but this has to be updated to make it work.

• remove old kernel packages from packagecloud
  • See package_cloud yank - https://packagecloud.io/docs#yank_pkg
• upload new kernel packages to packagecloud

[StefanScherer]

Fixed with https://github.com/hypriot/rpi-kernel/commit/0f85a8aaaa6473d50fd89cade392cc88356175ac