Repackaging release

This release fixes a packaging error in v1.2.1 where decompressing the image on some platforms would result in a corrupted file, which in turn would not flash correctly.

Tech specs:

• Linux: Ubuntu 16.04 LTS (ubuntu-mate-16.04-desktop-armhf-raspberry-pi)
• Kernel: 4.1.19-v7+
• Chromium: 50.0.2661.102

You can verify correctly downloaded & decompressed files with:

$ openssl sha1 chilipie-kiosk-v1.2.1.img*
SHA1(chilipie-kiosk-v1.2.1.img)= 30f4a20b11ab272092a512aad192ac06de24b7bb
SHA1(chilipie-kiosk-v1.2.1.img.tar.gz)= 85cb855e4b0565486193b35c893ad5d11bd91cd1

Thanks @matthewwicks & @paasovaara for reporting unpackaging issues on Windows!

Closes #20