Repo Re-Org, More like ROS Package

- Reorganize repo so docker stuff is
  a folder within fast_rrt_ros ROS package
- Update filepaths in README
- Update `build_and_run_docker.bash`
  to use main folder as build context,
  but use Dockerfile inside docker folder
- Update filepaths in Dockerfile

scripts/1_gazebo.bash

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+roslaunch husky_gazebo husky_playpen.launch