Fix shared_steps in DSL

[rjaros87]

There was mistake in shared_steps method. The * caused that Describer throw an error undefined method 'last' for "some string":String when try do this if @group_args.last.is_a? Hash

[akalineskou]

Here we are, almost 2020, 3 years have passed and this still isn't fixed... what a shame

[rjaros87]

@alex2005git probably this project died in natural way :)

[akalineskou]

I wonder why though, it's so useful, especially with capybara...

[nyarly]

The sad fact is that the company that built and maintained it shut down in early 2016. I haven't been using Rails enough in the interim to really make use of rspec_steps (and maintain it thereby). That might be changing soon, but it may be worthwhile to discuss adding a maintainer to the repo.