one pi zero code was wrong, and some overclock codes were too long
0.0.9
Now has both 24 and 25 bit options (see https://github.com/AndrewFromMelbourne/raspberry_pi_revision for more details)
0.0.8
- added overclocked raspi support - fixed raspi 2 chip typo - can override detection code with environment vars `BLINKA_FORCEBOARD` and `BLINKA_FORCECHIP`