make pry available in dev environment

can insert

    binding.pry

to create a breakpoint with REPL

http://pryrepl.org/
ability to focus rspec on specific spec(s)

you can add the ":focus" option to specific specs so that
rspec only runs those. example:

    it "should handle timeouts", :focus do
      logger.should receive(:<<).with(an_instance_of(Timeout::Error))

      MetaInspector::Request.new(url('http://example.com/timeout'), timeout: 0.0000000000000000001, exception_log: logger)
    end
Merge pull request #76 from jjb/dev-environment-stuff

Dev environment stuff