Use of Ruby 2.0.0-p247 is now recommended
Exports will now create a folder based the `VERSION` file, closes #4.

- If a version is specified, `spout export 1.0.1` then the command line version is used
- If no version is specified, and no `VERSION` file exists, then the default `1.0.0` is used
- The version must be specified on the first line in the `VERSION` file