Add motor example
rename motors to ABCD

Resolves tehviking/brick_pi_ruby#2

Conflicts:
	lib/brick_pi/bot.rb
rubyify port names

added underscores to match motors
Add rspec
Add configuration module
remove default motor/sensor initialisation
Remove sensor#configure
update README and examples to use create block
Merge pull request #5 from Floppy/rename-ports

Rename ports
Merge pull request #6 from Floppy/configuration-dsl

Create blocks to specify a whole robot
Merge pull request #2 from tehviking/master

Upstream changes