Fix bug in Command::Matcher::Place args_extractor()

args_extractor() should return a Pose object but was returning an
OpenStruct instance. Ultimately this makes it dependant on Pose, a
better solution would be to re-design the Pose class to accept a
hash of attributes to mutate itself.
Update bin/toy_robot_simulator to be executable

This commits includes a test for this feature.
Remove production dependancy on 'pry'
Rename 'tests/' dir to 'test/'

Updates RAKEFILE for running tests from the proper dir. Replaces
absoulute path 'require' for 'require_relative' in tests referencing
CommandMatcherInterfaceTest and ReporterInterfaceTest.
Change require('./') to require_relative() calls
Rename Command::Matcher to Command::Parser
Namespace /lib/* and /test/* to ToyRobot
Rename *toy_robot_simulator to *toy_robot
Add toy_robot.gemspec
Rename RAKEFILE to Rakefile for compatibility
Update bin/toy_robot to require 'toy_robot' gem
Update toy_robot.gemspec with versioned dependancies