Add gemspec file for gem

omniauth-msunet.gemspec

+# -*- encoding: utf-8 -*-
+require File.expand_path('../lib/omniauth-msunet/version', __FILE__)
+
+Gem::Specification.new do |gem|
+  gem.authors       = ["Troy Murray"]
+  gem.email         = ["tm@msu.edu"]
+  gem.description   = %q{Official OmniAuth strategy for Michigan State University MSUnet.}
+  gem.summary       = %q{Official OmniAuth strategy for Michigan State University MSUnet.}
+  gem.homepage      = "https://github.com/tdm00/omniauth-msunet"
+
+  gem.executables   = `git ls-files -- bin/*`.split("\n").map{ |f| File.basename(f) }
+  gem.files         = `git ls-files`.split("\n")
+  gem.test_files    = `git ls-files -- {test,spec,features}/*`.split("\n")
+  gem.name          = "omniauth-msunet"
+  gem.require_paths = ["lib"]
+  gem.version       = OmniAuth::Msunet::VERSION
+
+  gem.add_dependency 'omniauth', '~> 1.0'
+  gem.add_dependency 'omniauth-oauth2', '~> 1.1'
+  gem.add_development_dependency 'rspec', '~> 2.7'
+  gem.add_development_dependency 'rack-test'
+  gem.add_development_dependency 'simplecov'
+  gem.add_development_dependency 'webmock'
+end