mspec :foobar raises a ZeroDivisionError

[eregon]

$ mspec :foobar
$ ruby mspec/bin/mspec-run :foobar
mspec/lib/mspec/runner/formatters/spinner.rb:54:in `/': divided by 0 (ZeroDivisionError)
	from mspec/lib/mspec/runner/formatters/spinner.rb:54:in `compute_percentage'
	from mspec/lib/mspec/runner/formatters/spinner.rb:62:in `compute_progress'
	from mspec/lib/mspec/runner/formatters/spinner.rb:84:in `start'
	from mspec/lib/mspec/runner/mspec.rb:99:in `block in actions'
	from mspec/lib/mspec/runner/mspec.rb:99:in `each'
	from mspec/lib/mspec/runner/mspec.rb:99:in `actions'
	from mspec/lib/mspec/runner/mspec.rb:54:in `process'
	from mspec/lib/mspec/commands/mspec-run.rb:83:in `run'
	from mspec/lib/mspec/utils/script.rb:270:in `main'
	from mspec/bin/mspec-run:7:in `<main>'

[eregon]

Fixed by a6a6c95