Merge branch 'set_provider' of https://github.com/pronix/vagrant-libvirt

lib/vagrant-libvirt.rb

@@ -28,3 +28,12 @@ module VagrantPlugins
   end
 end
 
+# set provider by bash env
+# export VAGRANT_DEFAULT_PROVIDER=libvirt
+Vagrant::Environment.class_eval do
+  def default_provider
+    (ENV['VAGRANT_DEFAULT_PROVIDER'] || :virtualbox).to_sym
+  end
+end
+
+