Also re-numbers energenie sockets 1-4 (as noted by @bennuttall in
comments to #239), and adds several "real pins" tests and board tests.
The bad-PWM stuff is currently disabled as it causes segfaults when
running the tests and I can't seem to trace the cause at the moment.
Finally, I've tweaked the deb config to suggest gpiozero, removed spidev
as a mandatory dep (which'll fix installs on wheezy for py3), and
there's some more miscellaneous last-minute stuff here that I can't
recall...
Change MockPin (and MockPWMPin) to make them behave more like 'real' pins - fixes#206
Add new MockPin tests, and rework some of the existing ones
Incorporate #216