Gemfile in spidey-mongo-0.2.0 vs Gemfile in spidey-mongo-0.3.0

@@ -1,12 +1,24 @@
-source "http://rubygems.org"
+source 'http://rubygems.org'
+
+case version = ENV['MONGO_VERSION'] || 'mongo2'
+when /^moped/
+  gem 'moped', '~> 2.0'
+when /^mongo2/
+  gem 'mongo', '~> 2.0'
+when /^mongo/
+  gem 'mongo', '~> 1.12'
+  gem 'bson_ext'
+else
+  fail "Invalid MONGO_VERSION: #{ENV['MONGO_VERSION']}."
+end
 
 # Specify your gem's dependencies in spidey-mongo.gemspec
 
 gemspec