Remove development dependancies from Gemfile
Best practise to have them defined in the .gemspec
Change to https for Rubygems
Fixes issues running Bundle install in Ruby > 1.9
This is a workaround until https://github.com/mark-moseley/ruby_core_source/pull/16 is merged...
Lock down versions in .gemspec
Also defined development dependancies and locked
those down too :+1:
Merge pull request #41 from petems/clean_up_gemspec

Clean up gemspec