Rake task init_new_gem uses very outdated templates

[jmarrec]

Ruby is outdated the extension gem version is 0.3.1 (when 0.8.0) is current, etc

https://github.com/NREL/openstudio-extension-gem/blob/406aec4c8c5a4be6b5b649b1d9d714bf83fdbe48/init_templates/gemspec.txt#L32