Create version file and use it for Rakefile, instead of parsing with regexp...

[davispuh]

Create version.rb file for version info, like typically gems do. Advantages are that doesn't have to include everything just to see current version, for example in gemspec. Also in Rakefile use this file, instead of manually parsing with regexp.

Also added dependency versions to gemspec to avoid warning (about how it's not recommended) when building gem.

[greysteil]

What's the status of this? Looks like a bunch of other PRs are waiting for it.

[davispuh]

@leejarvis Looks like you're really busy? What about if I create new beta branch and merge PRs there and then when you've time you can review them all and merge in master. But in meanwhile I can manage that beta branch.

[leejarvis]

@davispuh sure that sounds fine. I think this PR is fine to merge to master also, so go ahead

[davispuh]

Cool 😎