Recheck dependencies for unused stuff

[agarie]

There are lots of dependencies in the gemspec. Two questions that need to be answered:

1. Are they really needed? (probably yes)
2. If so, what version constraints we should enforce?

I think we need to go dependency-by-dependency and verify how lax the version requirement can be, thus updating the gemspec to reflect that.

[mikecmpbll]

I'm confused about the gsl dependency. I'm trying to install statsample + optimisations for Ruby 2+, but the statsample rubygem (SciRuby) has an rb-gsl dependency, and the statsample-optimization gem (presumably https://github.com/clbustos/statsample-optimization ?) has a 'gsl' dependency. As far as I can tell the 'gsl' gem won't work with anything above Ruby 1.9 (it's failing to install for me, anyway).

Extra confusion also in that the rb-gsl gem isn't SciRuby's but this one instead: https://github.com/blackwinter/rb-gsl

(i'm trying to calculate a multiple linear regression but it's taking too long, wanted to see if the C bindings in the optimization gem sped things up.. and by the way i've no idea if that gem would even speed that up :)

[mikecmpbll]

Also, much of people's confusion about which repository is responsible for the "statsample" gem could be prevented by updating the "Source Code" URL in the RubyGem gem settings, which still points clbustos's repo.

[agarie]

The statsample-optimization gem is quite old -- the last release was in 2011. We do need to update it, but I'd prefer to work on this gem before optimizing it. :)

Also, I updated the links in rubygems.org for Statsample, Distribution, Integration and Minimization. Thanks for pointing that out.

[mikecmpbll]

Perfect, thanks :)